Yume Nikki/WMG

Madotsuki can generate any area in her dream world, and develop any new effects, and likewise destroy them.
Evident that Kikiyama is "updating" this game. If something was to be added, it may raise more questions than answer them. And what if they directly contradict any theories us Tropers have created?

Madotsuki is blind in real life.
But there wouldn't just be a world of eyes in her mind if something didn't happen to her eyes. Maybe they were gouged out during times when she was raped, or when she murdered someone, depending on which theory you follow.

Madotsuki was raped sometime before the events of the game took place.
It's come up before, and it seems to be prevalent, so let's look at the evidence.
 * 1) Possibly the biggest clue is within the 'Kyukyu-kun' room, here (ignore the commentary) -- after entering the room, she sees a happy, smiling, phallic-looking rainbow thing rubbing the railing, looking for all the world like an unassumingly friendly creature. When Madotsuki enters the next room, she is confronted by a menacing, aggressive-looking face and immediately wakes up from the dream world. Whether it's a coincidence or has some underlying meaning has been argued about a lot. It is, however, worth noting that FACE is the one and only thing that wakes Madotsuki up that isn't caused by Madotsuki herself. It also doesn't help that the door leading to the Kyukyu-kun room looks a lot like a zipper.
 * 2) There are a few places in the game where some of the items or areas look like vaginas -- bleeding orifices (like the door to the Kyukyu-kun room, which has to be knifed open, leaving a bizarrely hymenal opening); and the tunnel into the forest has these floating, multicolored creatures that look suspiciously like uteruses...with eyes.
 * 3) Also, there are lots of hands throughout the game; the staircase to the poop-hair room is lined with them, and there's also the medamaude room where they're sticking up from the ground (and there are bodiless legs wandering around - would those fit into it all?). Unwanted touching, perhaps?
 * Perhaps she's not only been raped, but is also pregnant. One room has figures full of figures with huge, bloated abdomens. Another room (the room with the pitcher NPC who spills blood from his head, and the pool of blood) features a poster on the wall of what appears to be sperm surrounding an egg.
 * Maybe this is stretching things (but then, this is a dreamscape), but consider the NASU mini-game. In that case, "Nasu" is obviously "eggplant" (茄). Thing is, there's another Japanese word pronounced "nasu" (為す). Usually, it means such things as "to achieve", "to build up", "to change into", etc. However, there's also an archaic meaning of that word--"to have a child".
 * More evidence: The place Uboa transports you to. The creature in the back palming huge bits of the landscape looks vaguely like a nightmarish, distorted incident of groping.
 * Not only that, but you're shoulder-deep in thick, sticky white fluid...
 * After crash-landing on Mars, Madotsuki can descend into a volcano. Inside is a boiler room, inhabited by an enormous, one-eyed, constantly crying creature. Given that it's phallic, it could suggest that the rape took place in the boiler room of her school--a janitor or teacher, perhaps? Under this logic, Masada, who has "sensei" in his full name, may have been a sympathetic music teacher that suspected what was going on, but was never able to prove it. In her dream, he leads her to her assailant so she can accept the trauma. Stabbing the creature changes his eye from a malicious red to a clear blue--perhaps a suggestion that her striking out against him opened his eyes to how much he hurt her. The constant weeping may suggest remorse over his actions, or it could just be...maybe it's time to stop now.
 * So you're using a fan-made nickname for an unnamed character as part of a theory?
 * Well, when all you have is a hammer...
 * Boiler room... dreams... Freddy...?
 * Boiler room... dreams... Freddy...?

Madotsuki achieves a happy ending
After fighting through her inner demons, and collecting her thoughts,
 * 1) When inside the dream, you can still go to sleep and enter a new dream. In one area, you even have to go to bed a total of three times.
 * ...Inception.
 * 1) The object that appears on the balcony at the end out of nowhere... appears out of nowhere. It couldn't fit through the front door, which is somewhat suspicious
 * Seriously dude... don't. All this just raises bigger questions of this girl in an apartment no one else knows exists just has something appear on her balcony.
 * Where did they come from? How did they get in? Why are they there? Who put them there? If the building is as wide as Madotsuki's room, who else could be in?
 * 1) In a semi-hidden area, the witch power can be used to fly. Canceling it mid-air causes Madotsuki to leave the dream and fall out of bed.
 * 2) The bloodstain seen
 * 3) The last characters you see in the game alongside the bloodstain are dream-denizens: the onion/garlic-headed pink things.
 * 4) Not to mention that her eyes are always closed, "awake" or otherwise.
 * I actually got the feeling that Mado was just troubled by a cocktail of mental illnesses. There's evidence of schizophrenia, agoraphobia, gender confusion, social anxeity, autism, psychopathy... All the big ones. Maybe the stairs were always there and she just never saw them before. I think maybe the onion bell creatures that dance around  are a representation that , or that the apparitions were actually more real than previously thought.

Building off the After the End theory; The world has ended and Madotsuki is the last person on Earth. But she has a mission to complete.
More specifically, she's The Messiah. With the destruction of the world, a new world has begun to appear; a world ruled by demons and manifestations of fear, evil, primal emotions and memories, etc. However this world doesn't technically exist yet, it resides inside Madotsuki's head, since she's The Chosen One. She must enter this world and conquer it by facing these manifestations and collecting the Effects, which are whatever she wants them to be, because she's a God-in-Training. What's most important though is what she does with them in the Hub, or the Center of the "New World", at the end...

Madotsuki doesn't want to be a female
The phallic symbolism in her dreams is her penis envy, the uteruses in the forest leading to a man lying in blood symbolizes her masculine self dead in a pool of menstruation (her becoming a woman physically), and she has no problem using the men's portable toilet in the block world. She tries to force herself to be a girl mentally

Madotsuki is a male to female transsexual
The phallic multi-colored creature followed by a disturbing image is her rejection of her masculine side. She can barely interact with any of the female characters, and those who can be interacted with seem to be rejecting of her. The piano man seems to be trapped on a space ship with no control over it, and is overall a lonely looking person. When the ship crash lands on the strange planet, he seems sadder and reacts in surprise beforehand when the sirens are going off. This can indicate a masculine part of Madotsuki she is trying to send away. The orifices and uterus-like symbolism are her womb envy. This all can indicate that she is a male-to-female transsexual who has given up on trying to live in a world that would have trouble understanding her.
 * As an addition to both of the above theories, note the blue creatures wandering around the area after the flower corridor--one shaped like an X chromosome, one shaped like a Y chromosome, and one seemingly a mutated amalgam of the two. They could suggest gender issues in either direction.

Madotsuki was Dead All Along
She's a ghost trapped in the room she was raped and murdered in. The things in her mind are trying to help her forget her violent, untimely death, but only by accepting it and leaving the toys/effects they gave her behind does her gateway to the afterlife appear, manifesting as the

Madotsuki is a lucid dreamer
Madotsuki is actually exploring her broken, twisted dream world for a source of amusement. After finding herself in her room, an obvious dream sign occurs, her video game console is gone. When turning on the TV, she can find another dream sign; an eye or unusual pattern appears. Finally, she does something that she normally wouldn't do in real life; she walks out the door. The door room may be willed every time, and when she enters a door she takes a few moments to visualize the world she is entering. Inside the dream world, she seeks out as many fun abilities as possible that she can use. None of this would be normal behavior in a usual dream, as people generally behave as they would in an everyday environment, and Madotsuki would never decide to walk out of her apartment.

Madotsuki is a lonely, latchkey, "normal", depressed girl on the cusp of puberty
Rape, rape, rape rape, rape. No woman who has never been raped can be depressed, can they? Madotsuki is just depressed in a society that is kind of in love with suicide. All the phallic and menstural imagery could simply be a child afraid of growing up and going through puberty. She is probably a Hikkikomori or an autistic girl who only seems to be able to live in her dream world. Once she has seen all there is to see in her dreams, she feels that her life is over. So she ends her life. I do not know what the creatures at the end are supposed to mean. I think the creator of this game just wanted to creep people out and has not really established a solid narrative for this game.
 * Way to suck the fun out of Wild Mass Guessing, guy. :(
 * I'm not your guy, friend!
 * I'm not your- *is crushed by a falling cow*
 * Taking into account the other stuff on this page, this really would be a wild guess.
 * Given Kyukyu-kun's rubbing gesture and dildo-like appearance, he seems more like a metaphor for masturbation than rape.
 * Adding to the "latchkey" theme, the broken town might be a telling area. All those shadows living in a slum, making happy noises that don't reach their faces...and you see them in the sewers, too, mucking through the filth. To this troper, it suggests that Madotsuki lives in a bad neighborhood, and her parents are probably away a lot trying to make a living at crappy jobs--wading through shit for it. She probably hasn't really ridden her bicycle outside in a long time, maybe since she moved here, so it's precious to her in her dreams, and thus one of the few useful effects. Although, the "bad neighborhood" theory could also suggest a higher incidence of crime, and thus of rape or molestation.
 * Or at the very least, a potential fear of it; maybe that's why she hasn't ridden her bike lately? ("If you go out by yourself, then... 'bad things' might happen to you," and we know that modern kids have at least vague ideas about what those 'bad things' are.) She doesn't necessarily have to have suffered rape/molestation herself, but if the area she lives in is really the 'bad part of town,' which seems likely given the above WMG, then maybe her hikkikomori nature is the natural result of becoming too scared (of rape/molestation, harassment, crime, etc.) to go outside anymore?

Madotsuki is/was a budding serial killer
Either that, or she's not as sympathetic as everyone's making her out to be. A few of her abilities are pretty manipulative. (The knife...well, it kills things. And the cat ability makes others come towards her, and the stoplight makes things stop.) Madotsuki's a girl who's been bullied and wishes for revenge, but she's gone a bit insane, and therefore became a Hikikomori, and realizes she has a world that's in her control; her dream world. She then dedicates her life to discovering how much power she can have over her dream world, and at the end when she realizes that she's found everything she can and can't control anything further, she, well...you know. I'm sorry if this is a stupid theory, I'm just tired of people characterizing Madotsuki as The Woobie. The kid's messed up. And not in a sympathetic way, in my opinion.
 * And no, I don't hate Madotsuki. This is just an Alternate Character Interpretation.
 * I definitely see where you're coming from, but even in her budding serial killer-ness, there could be something to sympathize with. (She is probably still just a child, after all.) Like you said, maybe she's just a shy bullied kid in her waking life, the world in her mind is her own sanctuary of control that she can retreat to, and things she does in her dreams are manifestations of repressed feelings that will never emerge as actions in her waking life. But I don't see how she could ever run out of things to dream up and control. Maybe she just "you know"'ed after realizing that her dream life was just a big lie, and her real life would always intrude at some point?
 * Alternately, she's awake all the time. The dream world is her after her antipsychotics wore off, and she doesn't want to go outside and face reality. Pinching herself is actually popping an antipsychotic and running home. Going to sleep just lets her sleep through the time until the antipsychotics wear off.
 * Is it wrong that I view her as even more of a sympathetic Woobie now that I've read this theory?

Madotsuki has severe hypertropia
Hypertropia is, essentially, googly eyesin real life. (Not, as you might imagine, a condition forcing obsessive additions to this wiki.) Due to the way Japanese society works, her eye problems would draw a lot of attention and probably discrimination, leaving her a Hikikomori and always keeping her eyes closed so it's not noticeable. The googly eyes that are more or less everywhere (including the place where Uboa appears) are her psyche reminding her of the fact. The black-and-white areas, which seem to represent her younger years judging by their art style, have occasional googly eyes in them as well. Masada, the most obvious example of googly eyes, is usually determined to be some part of Madotsuki's mind that she's trying to send off - in this case, her hypertropia and possible other mental problems (see: autism; autistic people do not interact with other people very well, and are often precocious in areas such as piano-playing). In fact, there are eyes everywhere, googly or no; the unsettling sequence in the refugee town where Madotsuki walks past a long row of shack with eyes on them, staring at her, might represent her issues about eyes, or maybe feeling like she's being put on a pedestal to be examined and ultimately judged. Why can she see fine, despite her eyes not pointing in the right direction? It's a dream, that's why.

Madotsuki needs to get laid
She's too hikikomori to do anything in real life. In dreams, of course, it's not a problem. Cat effect? Drawing things toward her? That's just suspicious. Uboa represents a penis. KyuKyu-kun is a giant dick. Masada? Attractive male with a dick, of course. Knife? Phallic imagery!
 * ...Wait, how does Uboa represent a penis? Because it ? And Masada actually seems pretty androgynous ...
 * Exactly. And you obviously haven't seen enough porn involving Masada.
 * Does that mean that Che Guevara represents a- *shot*

Madotsuki is a sleepwalker
The first place Madotsuki visits whenever she goes into her dreamworld is a replica of her apartment(minus the Famicom). The Nexus is the area immediately surrounding her building, and the other areas she visits are real places, albeit heavily distorted since she views them through the lens of her subconscious mind. The Effects are(mostly) real objects she picks up and uses when necessary.
 * But that would mean when she stabs something...oh dear.

Madotsuki is insane.
Everything in this game is a vision of her own insanity, including her death which could represent that she completely lost her mind, everything that she obtains during the game could represent the phases of her life, the bike could represent riding through the park, the fat could represent her being overweight at some point, at some point, she probably could not handle life when she tried to keep up with everyone, and the knife could represent her going over the edge to make sure she doesn't have to keep up with them, only staying in front of them, placing her in mental care, with the room representing the only safe place in her mind, with the people waiting at the door being the reason she won't open her door, and when she goes asleep, they leave her alone, letting her leave the room to find parts of her life that she knows, and at the end, she simply accepts it's all hopeless, and just dies, her sanity along with it.
 * She may have been losing a bit of her benevolence (Childhood innocence and all that), because in one of the areas, there is a fire, meaning she did not just use knives to kill people, but also killed them with more practical means, she also didn't seem to care about other innocents, just as long as she could stay ahead of all of them.
 * She may have become very anti social, because everybody was ahead of her.
 * Possibly, the effects also represent other things like emotion (Umbrella=Sadness), ways she mercilessly killed her friends (Headless=Head cut off), as well as the desire to be noticed.

Madotsuki is depressed because she accidentally killed someone, possibly Poniko.
One of the biggest clues that she had killed someone is where you get the stoplight itself; on the path, there's a messy crime scene in the street, with the splattered remains of a man all over the road. While this may hint that the dead person is perhaps Masada or the proposed rapist in some of the entries, there's also hints with Poniko/Uboa herself, who's trapped in a room that outlooks a snowy land, and randomly turns into a horror who pulls Madotsuki into a hellscape when she turns out the lights. She blames herself for the death (by knocking her into traffic or causing some other similar accident on the road). Most, if not all, of the items that Madotsuki ends up finding pertains to something that was involved in the incident. The accident happened at a stoplight, on a snowy, slushy day. Madotsuki and Poniko had been both riding bicycles, on their way to someplace (oh hell, let's say someplace that sells frogs and flutes, so we can add the last two items into this list), when Poniko teased her friend about being fat and short. When she poked Madotsuki in the stomach, Madotsuki became angry and shoved her. Unfortunately, she shoved her a little too hard and pushed her into traffic, specifically into the way of an oncoming truck. A few seconds later, Poniko was nothing more than a mess of body parts, leaving Madotsuki in a state of horror and shock at what she had done. After this, she ends up falling into a deep depressing, repressing the memory of the accident and going into a hikkikomori state since she can't bear to join the world where she had killed her best friend. It's only when you collect all of the items together that her memory is clear. By doing this, you have pretty much doomed the game to a Downer End. All Madotsuki can do now is kill herself, by flinging herself off of her balcony. She had this plan for some time and only now had the ability to do it, since the balcony is the only place in the real world that Madotsuki will actually go to, and it's only at the end of the game where she has the tools (IE the step-stool, a representation of her memories) to enact it.
 * The blond hair and long hair both connect to Poniko. The Cat item (draws people to you, perhaps analogous to being just a popular person or likable in general) can also connect, but this is just speculation to me.
 * The hat and scarf, Yuki-Onna, and Snow items all connect to the weather on the day that Poniko died: cold, wet, winter day. It's a good chance the car involved in the accident couldn't stop or skidded out of control when it hit Poniko. The neon and lamp items also play into this as well, with the accident happening at night, at a place where neon lights are very common.
 * Given what the Stoplight does, I'd go one step further here - there was a red light, and the car should have stopped, but slid on the wet road. Perhaps they were roughhousing while crossing the street at a red light. So the Stoplight in her dreams does what the real one was supposed to do - it makes things stop, freezing them in place. But it also shows the mutilated body.
 * Judging by the severed head and Medamaude items, as well as the massive amount of disembodied body parts and creatures that are just a collection of body parts in random assortments, the car hit Poniko with such a force she was decapitated and lost an arm in the process. Even the Nopperabou plays into this, with having the effect of the head detaching from the shoulders and spinning wildly.
 * The triangle kerchief item is pretty obvious as far as items go: it's a Japanese symbol for ghosts. The towel (which goes over Madotsuki's head and entire body) can also be a shorthand symbol for ghosts, or could just be another sign of the weather on the day when the death happened. This could be a reference to just Poniko being dead, and therefore a ghost, or be dark foreshadowing to the end and imply that Madotsuki wishes it had been her who died.
 * Demon, Poop Hair and Witch items are just how Madotsuki views herself now: a horrible, hateful person. A demon, a witch, just filth with a face and eyes. The knife also plays into this, but in a slightly more cruel way. It allows Madotsuki to kill in her dream world, stabbing everything to death possible. By gaining the knife, she can just call herself a murderer. Adding to this, I think Poniko is the only creature in Madotsuki's dreams that has a realistic scream when she kills her. Perhaps this is the same scream Poniko made when she had fallen into traffic.
 * Buyo-Buyo, Fat and Midget all involve what caused the accident in the first place. Poniko called her these things, and probably jiggled her belly a bit while making the buyo-buyo noise, probably while in the middle of a playfight.
 * And here's the two big items that play the biggest part into everything. The bicycle and the stoplight:
 * The theory makes sense, but I think you have the wrong victim. Monoko, when shown the stoplight, grows arms in places that could imply a traumatized impression of injuries, particularly the one sticking out of her head. What if Poniko were Monoko's sister or other relative (Theme Naming, you see) and is therefore angry at Madotsuki for causing the accident, resulting in the fear that transforms her into Uboa in Madotsuki's mind? Note that this interpretation isn't entirely mine; I found the bit about Monoko and the stoplight implying an accident elsewhere (though I can't remember exactly where) and went from there.
 * I think that Poniko, whether victim or just horribly shocked by the accident, was held in a special place in Madotsuki's heart. The place Poniko is found is in the most peaceful world, which can almost be described as beautiful. The sub world where she is found contains light pastel colors and is actually genuinely enjoyable to look at. The island where Poniko's house is in has a very atypical amount of symmetry in it, almost as if that place was particularly made to be a shrine to Poniko. Although there are some uncertainties of exactly who Poniko is in relation to Madotsuki. Mother? sister? relative? close friend? secret crush? not so secret crush? Whatever happened, Uboa is probably some form proof that whatever their relationship used to be, it is no more. Whether because she's six feet under, hates Madotsuki, Madotsuki hates herself too much to allow herself to see Poniko anymore, or they just plain drifted apart over time; Madotsuki clearly blames herself for the entire ordeal.
 * Based on all theories under this header, I concluded that Poniko and Monoko are two dream versions of the same real-life (dead) person. Poniko is the idealized girl in Madotsuki's heart, and Monoko is the girl's corpse, a "zombie". The name "Poniko" is probably what Madotsuki used to call her, as it does not sound like a real name.
 * Whoa there, remember that almost all names of the characters are fan names. Even in wild guessing they don't really have any weight.

Madotsuki is a serial killer.
She's not a hikkikomori. She's under house arrest. The dream characters and places represent her victims or aspects of her insanity. is her atonement for her killings. Either that, or she wishes to.
 * The Toriningen are her murderous urges. The Lunatics send her to an inescapable room--allegorical for how giving into her insanity landed her under house arrest.
 * Monoko was the first of her victims--a little girl Madotsuki babysat and brutally murdered and mutilated. The fact that she's perfectly normal until Madotsuki uses the stoplight effect on her symbolizes that she was the weakest of Madotsuki's victims--she had tried to run, but all it took was for Madotsuki to say "Stop", and her fate was sealed.
 * Monoe was Monoko's older sister and a former classmate of Madotsuki's. She was the only one who knew who killed her little sister, so she had to die as well. She teleports Madotsuki away because she doesn't want her killer anywhere near her.
 * Masada was Madotsuki's piano teacher, who she was very close to and eventually developed a crush on. When he rejected her advances, she decided If I Can't Have You and killed him.
 * Poniko was her most recent victim, and the one Madotsuki feels most guilty over. The two were the best of friends in the past, but Poniko grew distant and started ignoring Madotsuki. At this point, Madotsuki had figured out that her victims were appearing in her dreams, and so killed Poniko in order to keep her forever.
 * Uboa represents Death. He periodically appears in Poniko's place to remind Madotsuki that, although her victims may be alive and (relatively) well in this world, they're still dead at Madotsuki's hands in the real world.
 * The Number World and Block World both represent prison. The Number World normally has small, one-digit numbers (years in her various sentences, perhaps?), but also a few absurdly long numbers (prisoner numbers?). The blocks, obviously, are cells/cellblocks.
 * Madotsuki's killings generally happened on winter (Snow World) nights (Dark World/Candle World), and, of course, the most frequent weapon was a knife.
 * The Cat effect symbolizes that all of Madotsuki's victims were close to her. A child she babysat, a classmate, a teacher, a friend. Never strangers.
 * Shitai-san (the corpse you get the Stoplight effect from) might be another victim, or just a symbol of what Madotsuki did with the bodies of her victims--left them in the middle of the road in order to make it look like they had been hit by a car.

Madotsuki cannot control her dreams.
But she remembers every detail; wandering through places that are twisted and wrong, an overwhelming sense of dread, every seemingly friendly face turning twisted and frightening for no reason; and, worst of all, that she frequently just isn't herself. She just gets worse and worse each night. By the time the game starts, she's to terrified, and her sense of what's real is so damaged, she won't leave her room. In the end, she takes the only route she can to escape her dreams.

Madotsuki is a Narcoleptic
Narcolepsy is a disorder where the sufferer randomly falls asleep and is unable to control it. Another symptom is vivid hallucinations. Narcopleptics are often unable to lead normal lives because their sleep pattern interferes with regular activities like attending lessons and hanging out with friends because there's a chance they'll pass out and injure themselves. Madotsuki became a hikikomori (and eventually became depressed) because she was frustrated with her condition. This also explains why the city looks so empty when you stand on your balcony. It's the middle of the day and all the 'normal' people are at work or school.

Madotsuki is much more intelligent then the average teenager

 * For one, Madotsuki is ambidextrous, which is a sign of intelligence (she can hold the knife in both hands). She also seems clever enough to get around, figure things out and survive in a world filled with monsters even if it is just a Dream World. Next, depression/suicide is known to run highly amongst teens with high intelligence. I would take this a step further and say she might even have Asperger's Syndrome, but I'm not familiar enough with the syndrome myself to make a proper theory.

Madotsuki is an Angsty Surviving Twin.
Some people have speculated that twins form a strong bond with each other in the womb, and that when one of the twins dies early on (miscarriage, stillbirth, etc.) the survivor may experience a kind of non-specific grief throughout their life, often saying that they're searching for "something" that they've lost but can't quite name or describe. Assuming there is some truth to this notion, it seems to me that many aspects of the game and the above theories suggest that Madotsuki was conceived as a twin, but born alone.

Most of the gameplay consists of wandering around an unsettlingly empty dreamscape, alone and hopelessly lost, without any clearly-defined goals other than looking for "effects," whatever THOSE are; the instructions provided in the intro screen are decidedly vague and unhelpful. In addition to all the obvious womb imagery, notice that the effects appear as eggs- symbols of fertility and gestation- when dropped in the Nexus. Perhaps the effects are nothing more than decoys; they only vaguely resemble the true object of Madotsuki's wanderings, but in the end, she discovers they can never be a suitable replacement for what she ultimately longs for. After finding (and rejecting) some two dozen bogus womb-mates, she finally breaks under the sheer weight of her own loneliness and turns to the only option left to her.

The much-discussed gender ambiguity could indicate that Madotsuki's twin would have been a boy, so she feels that her "other half" is male. On the other hand, there's Poniko, who is probably the most obvious and likely candidate to fill this role. She lives alone in a shrine-like structure that Madotsuki's subconscious has clearly decided is a Very Important Place; the interior somewhat resembles Madotsuki's room, suggesting (as someone else pointed out) that Poniko and her room may have originated as an early draft of Madotsuki and hers; Poniko does not respond to Madotsuki's presence in any way (Knife and Cat notwithstanding), perhaps because unbeknownst to the latter, she's already passed away; and when Madotsuki attempts to get her sister's attention by repeatedly flicking the lights on and off, Poniko finally does respond- in a rather nightmarish and traumatizing way. Insert your own joke involving Che Guevara and dead fetuses here.
 * Che Guevara is Madotsuki's miscarried twin brother.

Madotsuki is pregnant.
FACE is what she thinks will happen if she ever leaves her room, confesses being pregnant to her parents, and if the baby is delivered. If you look closely at FACE, it resembles a vagina being stretched open by foreign objects/utensils. FACE is the child she imagines.

Madotsuki wants to be male, and despises being female.
She goes through the "zipper door" and sees the phallic rainbow. This represents her wanting to be male, and hopefully "checking" for a penis. She's disillusioned when she unzips the pants she's wearing (except she's wearing a skirt in the game for some reason) and sees a vagina. FACE is her clitoris being stretched by strange metal utensils, seemingly an attempt to disfigure her female genitals out of hate and desperation. The evil-looking face on...well, FACE is a manifestation of how she loathes being a female.

Madotsuki's dreams are her only remaining memories
Some unknown, traumatic incident caused her to forcefully shove everything into the back of her mind. She "forgot" everything, and is scared of leaving her room because there very well MIGHT be something worse than a few nightmares going on outside unbeknownst to her. Also, the door is locked from the outside or she locked it herself just before she "forgot" and hid the key away, hence her shaking her head. Her dreams contain images and clues of her past. She searches for more about herself in said dreams.

She later realizes that her cryptic dreams alone won't reveal everything, and she must either somehow get out of her room and seek answers, or just kill herself and end it all. She goes "eff it" and jumps off her balcony, letting fate decide if she survives or not. Whether that was the key to her room she found and it just happens to be red, or a blood stain at the end is completely up to you.

Madotsuki is in Hell
She was murdered, and woke up in Hell. This is not her room, and the door is locked. Her dreams are her reflecting on what happened in a somewhat distorted way. On the ceiling in the room, which it appears that the player is looking from, is a carved painting explaining her demise in excruciating detail.

But she's fooled herself into believing it's all just a dream, and that if she goes back to sleep, she'll wake up and her normal life will resume. She eventually finds out she can't go back to reality, and the only way to break the "cycle" is to somehow "kill" herself in the after-life. She jumps off the balcony. The blood stain is there, but the jellyfish/dream creatures appearing around it imply that she didn't escape.

Madotsuki is in Heaven
Madotsuki was a Strange Girl with a love of all things weird, horrific and/or mysterious. Outside these things, she lived a boring life composed of school, piano lessons forced by her parents (though she did enjoy the company of Masada-sensei), and mostly being ignored by peers, save for a few acquaintances. A world where nothing is ever boring and there's always "something there" is her paradise. She has a lot of fun already, but wants more. The door is locked for more of a thrill. She decides to jump off the balcony. Jellyfish appearing around the bloodstain mean that she just went off to have more adventures in this weird world of hers.

Madotsuki's not a Hikikomori; she's just really sleepy.
What do you think you're doing, trying to make her go out in the middle of the night like that? A growing girl needs her sleep. You big meany.
 * But she doesn't have a toilet in there!!

Madotsuki is locked in her room by an abusive parent.
This is why she can't get out; She tries to open it, but try as she might, it won't open, so she shakes her head. Her dreams are all abstract representation of things she's done and people she's known/befriended, and even the memory of a pet frog and cat, before being trapped, and/or the abuse and threatening her parent has inflicted on her. After collecting all her memories OR "effects" in her dreams, she realizes that even if she were ever let out, she'd still lead a horrible home life. She decides to end it all, hoping to be reborn as someone with loving parents and a happy life, or to meet her friends in the afterlife someday.

Madotsuki is only dreaming part of the time.
Usually, she's just hanging out in her completely normal world. One night, though, she had a dream where she was a hikikomori who refused to leave her room. This was a nightmare for her, thinking of being so completely cut off from society; unfortunately for her, this dream was recurring. Finally, sick of the nightmare, she decided to try and end it:.

Madotsuki is a patient in a mental institute. The whole game is her hallucination.
In the end, she is finally let out, which feels like a "leap" for her.


 * To support this theory, the Toringen (Exuse the spelling), are other inmates at the asylum. Some are actively insane, thus the Toringen that chase Madotsuki. Others are capable of going insane if provoked, thus why a calm Toringen can be stabbed, and will go insane. Poniko is a nurse. She seemingly cannot hurt Mado, but suddenly, out of nowhere, the doctor comes, and the nurse goes away. Uboa is the doctor. When the doctor comes, he comes from nowhere (Thus Uboa's event being random, and coming from nowhere). It makes the world seems dark to Mado (Thus the lights needing to be off for Uboa to appear). The doctor has to touch Mado, and this makes her upset, and feel trapped (Thus when you touch Uboa, he sends you somewhere you can't get out of). The doctor may have to touch Mado in ways she feels is bad, and "wrong" (Thus the touching monster in the background, who appears to be squeezing breasts...). The doctor may also need to take blood samples from Mado, and needles could possibly scare her, or make him seem like a bloodthirsty animal in her warped mind (Thus the blood on the touching monster). Mado knows she can't get away from the doctor (Which is why you cannot get away from Uboa's trap). Mado may feel that the way the doctor has to touch her is "inappropriate" and is afraid that he will rape her (Possibly the touching monster again, and the wite fluid, that could be sperm/semen). The white of Uboa's area represents the white walls of the doctors office and his clothes. Mado knows that she cannon escape, but she tries to when he touches her (Thus Uboa's changing, possibly annoyed expression when you touch him). The doctor is intrested in Mado's mental issues, but otherwise does not force anything questions on her, unless she provoke it (Thus Uboa coming towards her when you use the Cat effect, when he doesn't move on his own). The whole game is her haluciation, as stated above. When you drop the effects as eggs, this is her trying to control her own insanity to beable to leave. When she jumps off her balcony in the end as said above, this is her getting out of the asylum, and it feels like a leap to her. The bloodstain at the end, however, shows that she was not ready to leave, that she was still insane, and the jellyfish represent that her insanity was still there when they let her go.

Madoutsuki is traumatized by rugs
Those Aztec Gods that she's terrified of? They're the embodiment of the rug in her bedroom. She keeps trying to throw it away, but it always comes back. Also, the rug is a Time Lord.

Madotsuki has an eating disorder
I'm surprised that this hasn't been mentioned at all, but have you ever wondered why she's always slightly bigger/thicker than most people in the dream world? Also, those creepy monsters with the mouths on their stomachs represent her self-image, combined with the Fat Effect, and in the room after those monsters, pressing the buttons that makes those spleen things vomit blood clearly represents bulimia.
 * At first I thought so too, but then I realized she's no thicker than the protagonists of the other games in the "series". The vomit thing still makes sense, though. Maybe she had one in the past.
 * That's because many of the fangame characters are edited from the Madotsuki sprite.

Madotsuki's eyes are always closed because she is asleep.
Even when she is awake, her eyes are shut. So, maybe she's just dreaming all of the game. Also, after she commits suicide, it shows a bloodstain and two jellyfish, suggesting she may still be in a dream/is waking up from the one she was just in.

Madotsuki owns or owned a copy of Bokosuka Wars.
The 8 bit world has a "Boss Room" with characters and music heavily reminiscent of it.

Tied with the above, Madotsuki's experience with videogames is because she traded the ones she had with other kids.
She traded the games because she didn't have money to own many games in the first place. However, most likely they bullied and discriminated her, and the trades were often unfair. NASU is the only game she has left.

Madotsuki is a better gamer than all of us.
And that's why she can actually play NASU.

Madotsuki doesn't open the door because this isn't her apartment.
She got in by parachute. She was interested in exploring the building, which was locked at ground level. It was locked because hallucinogenic fumes rendered it uninhabitable. Still slightly woozy, she mistimed the release of her parachute when jumping down, and landed hard but non-fatally, resulting in a pool of blood (as opposed to a pool of splattered corpse).

Madotsuki was born in Japan and moved to America.
This would explain the Blond Hair effect a lot- racial tension lead to her wanting to be white. It would also explain the Toringen party (American girls doing American things that she just plain doesn't get, leading to social isolation), as well as the Meso-American themes. If she was in fact raped, it could explain the situation a little more (especially if it happened before she learned English), and why she keeps her eyes closed (again, embarrassed at her race). Masada-sensei might have been a Japanese-speaking music teacher at her school who helped her learn English. The Uboa event could be symbolic for culture shock - she spends every day/every flip of the light switch in normalcy, until one day it changes suddenly and goes to hell. Poniko being blond supports this theory. Also, the lack of strictness of American gender roles, as well as sexuality in general being far more explicitly referenced, might have lead to gender confusion/triggered gender dysphoria, fitting into the theories that she is transgender in some way. All of these things might have lead to her becoming a Hikkikomori (which, although most (if not all) of the western world would find it suspicious, her Japanese-raised parents wouldn't think so much of it).

Madotsuki is in fact an interdimensional horror.
...Who caused an horrific event in the area and would have continued, but was stopped by a bunch of plucky heroes who erased her memory of her true nature and forced her to revert to a human form. This explains why she so reluctant to go outside and why her building seems to be the only thing around: there's nothing there. It also explains her dreams, it's her true nature manifesting itself to her. Collecting those effects? It's her previous identity coming back to her. And it also handily explains the ending:

Madotsuki is a test subject for some sort of sleep drug.
The drug gives her very strange dreams, and even dreams within dreams. In the end, she doesn't  but rather, wakes herself up from the drug induced dreams. The blood stain represents how she "died" in her dream world.

Madotsuki is God
She has weather controlling powers, as seen with Umbrella, Yuki-onna, and Demon. There is also a possibility that some of her effects are disguises(Blond, Towel, Frog) so that she can go into the human world. The whole game was her looking down on the world, and. Poniko/Uboa is Satan, and the Toriningen are demons.

Madotsuki lives in the North Pole, and does not leave her house due to the cold
Even though it does not show on her balcony, there is a chance her balcony could have a wallpaper-type thing over it, or she could be hallucinating what goes on outside due to not remembering what outside looked like. The snow world in the game is her way of going outside without being cold. Yuki-onna and the Hat and scarf effects point towards this.

Madotsuki used to have an obsession with harem anime and games
Harem, games or animes or mangas in which many, many people fall in love with one person, were one of Madotsuki's past addictions. She would play them daily, watch them daily, read them daily, and loved them. In her nightmares, the girl's she loved in the game's came back as violent women, AKA the Toriningen.
 * Her computer was taken by her parents after her addiction started effecting her health.

All of the original world's are pieces of Madotsuki's personality
Her room represents her scared self, since she wants to be here the least.
 * The Nexus is her aware self.
 * The Snow World is her cold self.
 * The Number World is her smarter self. It could also be her innocent self, believing there were no problems if she knew a lot. (She didn't know about the dangers of pedophiles at the time, which is why it is near Kyuu Kyuu-kun and FACE)
 * The Neon World is her playful, childish self.
 * The Shield-Folk world is her odd self.
 * The Candle World is her insecure self, because of the bully Toriningen, and someone who is also short like her(Midget), but is much faster and more talented than her. It could also be her religious self.
 * The Eyeball World is her feeling like she is being watched and expected to be perfect.
 * The Graffiti World is her perverted self, which is why there is a men's bathroom there.
 * The Dark World is her lonely self, because she can't find any friends there.
 * The Puddle World is another part of her insecure, self-conscious self.
 * The Block World is her "normal" self.
 * The Mural world is her killer self, full of pictures of everyone she has killed.
 * The Forest World is her drug-addict self, which is why she see's cat hallucinations there.
 * The Balcony is the place where she remembers everything she has done, which is why

Poniko is a nun.
Uboa looks like a nun's hood. Madotsuki used to be very good friends with Poniko, but at some time or another, Poniko suddenly decided to become a very devout nun (this is her turning into Uboa). Afterwards, when Madotsuki tried to talk to Poniko, Poniko dragged her into very devout religious rants and rituals-- the looping area where Uboa teleports you to is quite Satanic-looking, and it's inescapable. The on/off light switch action required to turn Poniko to Uboa is symbolic of Poniko's sudden, jarring conversion.

The whole Poniko/Uboa event is supposed to be a parody of "Thank you Mario! But our princess is in another castle!".
Poniko is thought to be the Princess, then BAM, when you hit the switch, Uboa is suddenly there 1/64ths of the time... mocking your futile attempts to get her to react and implying that she's in a different castle. Then you go to a completely different world.

Uboa looks like Che Guevara
Compare this to. He does. (Hey, if WALL-E can have a WMG just saying he looks like E.T...)
 * I couldn't help but 'shop that after seeing this WMG and laughing a lot.
 * Uboa is also the killer from the Scream movies and the first Scary Movie.
 * Maybe she's just a very emo Shy Guy?

Masada is also from the white desert
I'm not really going on anything other than his lack of color. But when you think about it, doesn't it seem likely that he's the same "race" as Monoe and Monoko? Looking at things from a psychological point of view, perhaps he lived in that area of Madotsuki's mind before something made her want to send him off.

Uboa also has messed up dreams...
When Uboa transports you to a place, Uboa really transfers you into its dreams. Which is also messed up in all sorts of ways. Dream within a dream anyone?

Masada and Uboa used to be the same.
Twins, Separated at Birth, two aspects of the same being, maybe even Comedy and Tragedy. They look sort of similar, the face scheme anyway, but act in different but possibly related ways. Uboa stands there and never does anything to harm the player; all he does is transport you to a nightmare realm you can't escape without waking, and his happysad expression falls and becomes completely sad if you touch him and get transported there. He could just want a hug, but is too afraid to hug Madotsuki in case he transports her to the other realm like he does everyone else, and can't do otherwise. Masada runs from you if you have the knife equipped, but other than that he seems to be a nice, if shy person. It's difficult to tell with the lack of dialog. Uboa doesn't seem to be much different, except that his mask (if it is a mask) covers his whole body (perhaps in hopes that it can keep people from being transported if they only touch the mask?) The differences could be that Uboa is used to hurting (or at least inconveniencing) anyone who gets close, and Masada may be used to being hurt, or, after being separated from Uboa, having his one defense taken away (even if it did stop anyone getting close).
 * Does this mean that Che Guevara is...oh never mind.
 * Yes, yes it does (for once. Che Guevara does look more like Masada than Uboa, in this troper's opinion).
 * Masada is the real-life photograph Che. Uboa is the stylised pop-art version.
 * Uboa and Masada are the same. They "both" raped Madotsuki.

Poniko isn't a character.
That girl? That's just Uboa wearing a "skin".
 * Alternately, Uboa is Poniko wearing a costume.

Uboa is hips.
As one user on Uboachan painstakingly pointed out, Uboa looks very similar to the ... curve of hips and thighs...
 * Can connect to the 'was raped' theory, touch the hips, get transported into the horrible grope-background, sticky-white-fluid land.

Almost all the characters are friends/acquaintances of Madotsuki. (And she also had a really crappy childhood.)
Building upon some of the other WMGs above, and said elsewhere...
 * Monoko is (Or represents) one of her first friends. She was killed in front of Madotsuki's eyes when they were playing near a traffic light, and she got hit by a truck. Being young, Madotsuki didn't really understand what she saw, hence why Monoko is represented as a mutated girl, rather than a mangled corpse. Madotsuki feels guilty over this, and blames herself a fair bit.
 * When you check Monoko, the game cuts to a detailed version of her rotating and zooming in and out while playing that oddly catchy rhythm. This is probably an indication that the event left a very large impact on Madotsuki when she saw what happened. It left a very large impact on Monoko too!
 * Monoe was another friend of hers who drifted away. Either she moved, or simply made other friends, hence why she fades away.
 * Masada was her music teacher with a lazy eye. while all the other students mocked him, she enjoyed him and his classes. Perhaps she learned to really harness her imagination with him, telling her about various books that really opened her eyes. Presumably, he got transferred to another school.
 * Any explanation for why he runs from you if you have the knife, then?
 * The original teacher was always quite shy, and a bit nervous and cowardly. Perhaps he wasn't transferred as much as quit after being threatened by a student in an act that stuck in Madotsuki's mind.
 * Toriningen are how Madotsuki saw other girls. Being short for her age, she saw them all as tall, and bizarre looking with their makeup and weird hairstyles, clucking away about things she didn't understand. Either they ignored her (And had fun without her, hence the Toriningen picnic she can't get to) or they mocked and bullied her, hence the psycho Toriningen.
 * What about the friendly Toriningen in the Numbers World?
 * Those fit under 'ignoring her.' Those Toriningen don't actually help her, they just leave her alone. it's not like every girl in school picked on Madotsuki. Hence why some are just weird looking, while some are malicious. As for the Toriningen in the department store who changes your menu, I'd say that represents one time when she recognized a girl that picked on her at school working at a store she was shopping at with her parents one day. The dissonance between this girl she thought was nasty, and seeing them be a polite server, made her confused.
 * This theory would indicate that Madotsuki had bigger problems than just being lonely or emotionally repressed; it's likely that the horrific death of her friend stunted her maturity as well as her ability to relate normally to others. Being 'confused' by one's school facade vs. their job facade is something that would happen to a young child; in order for one of Madotsuki's classmates to be working at a store, they'd have to be at least in junior high, more likely in high school-- Long after Madotsuki should be able to comprehend such things without such confusion. We might be surprised that the bitchy girl at school could seem so polite and friendly at work, but we'd accept it without more than a second thought.
 * Now, the big one. Poniko was the last friend Madotsuki had. Poniko seemed to be a kindred spirit, somebody who didn't talk much and didn't have any friends. Indeed, it wasn't much of a friendship, as Madotsuki simply hung around Poniko, but Poniko mostly took advantage of, if not completely ignoring, her. Still, Madotsuki, emotionally repressed as she was, thought it was a friendship.
 * This all changed after months, or years, of this supposed friendship. What happened? Poniko raped, or tried to rape, Madotsuki. This is where Uboa comes in, representing how that girl Madotsuki thought she knew very well became a monster. Madotsuki tried to defend herself, and ended up grabbing a knife, killing Poniko. Utterly horrified at having who she thought was a friend attack her, yet also killing her, sent her over the edge, and she became a shut-in.
 * Or maybe Madotsuki got too close or clingy and Poniko (perhaps callously) told her to back off. Madotsuki, already sensitive from loneliness, takes this the worst way. After all, Uboa will transport Madotsuki if she just runs into Uboa: the knife isn't required.
 * That works quite well, actually. I suppose I was just trying to find a reason for the knife and all the supposed sexual imagery. But just being told to eff off by one you thought was a friend would be devastating to somebody as screwed up as Madotsuki. (As one Troper above said, who says she's completely innocent amid all this? The gal's messed up.)

Poniko is a revolutionary.
Inspired by the awfulness of Madotsuki's dream world, and not even her No-face pajamas bringing her emotional comfort, she decides to steal one of the TARDIS beds, come to the "real" world to get her medical license, and help the tormented souls, such as a hand-ectomy for Monoko that would not require bringing her to the shovel-beam. However, the rampant poverty inspired her to use a Latex Perfection mask or Magic Plastic Surgery to revolutionize oppressed and third-world companies, starting with Cuba.
 * My joke is slowly ascending to meme-status. Wow.

Mars-San is the Last of His Kind.
Some sort of an apocalypse took place on his planet and only he survived by taking shelter in the boiler room. He's crying because he misses his friends and family.
 * And his baby son was sent to Earth Kal-El style and now resides in a puddle near the Witch effect tree, and only comes out once in a while.

Uboa is indeed female.
Uboa's face seems to be a extremely warped noh mask. Noh is a type of traditional, musical theater in Japan and the mask is usually worn for a female role. (It can represent a youngster, old men, or nonhuman characters. Although the third option is the most likely case here.) Since the house Uboa appears in is inhabited by a woman (Poniko), it might mean Uboa is female.

Monoe is a net idol, and Uboa is her face minus the editing. Monoko is her younger twin sister, also dramatically shop'd and actually has terrible birth deformities.
Madotsuki is an internet addict, and discovers Monoe and Monoko. She quickly falls in love and becomes obsessed with them. Poniko, Madotsuki's less naive friend keeps being subjected to Mado's gushing over how they are the human personifications of Moe. It's kind of annoying. So, Poniko soon digs up pictures of Monoe without Photoshop magic and broadcasts them on 2ch. The true Monoe is now nicknamed "Uboa", after the sound of screaming many users made at the photos. The cute Monoe now fades away from Madotsuki. She handwaves this and goes "Well, Monoko's still cute, at least". That is, until Madotsuki (unintentionally, mind you) finds a picture of Monoko at a public place taken by another 2ch vipper, though it had yet to be broadcasted. This dramatically haunts Madotsuki, and she pretends Monoko and Monoe never existed. They still have their place in her nightmares, however.

Kamakurako is Madotsuki, and the toriningen are actual girls who bullied her.
The toriningen were mean, bitchy girls in Madotsuki's school, when she was younger. She mostly ignored them, despite what they said or did to her. Also, she (Madotsuki) had very long hair (hence the Long Hair effect). One day, they cornered her in the school boiler room, cut her hair very short and laughed at her. As a result, she became depressed and started wearing grayish-black clothes. Even when her hair grew back, she still felt isolated and eventually became a hikikomori.

Monoko and Monoe weren't friends of Madotsuki, it's quite the opposite.
Monoko was The Alpha Bitch, whose main target was Madotsuki. Monoe was her twin sister, and always tagged along, not ever saying anything, but giving a little condescending smirk. The toriningen were their group. Their cruelty, and Madotsuki's lack of real friends, save for Poniko, who eventually joined their group, eventually forced her to become a hikikomori. Madotsuki despised Monoko. In her dreams, Monoko is no loger a beautiful, tall girl, but a disfigured thing with extreme Body Horror. Madotsuki didn't like Monoe very much, either, but didn't hate her as much, so had her simply disappear. Poniko was her friend, and she never saw her turning into "Uboa" coming.

Uboa is a dimensional traveler.
The thing is, the dimension he is from is entirely different from our own, one where he is normal. He enters Madotsuki's dream world entirely unaware of his effects there or how people will react when he suddenly appears and does nothing but observe. Touching him breaks his equipment and tosses both people into a random dimension, he doesn't know this, however, as he has no idea how this dimension works.

Masada was an older friend of Madotsuki's who she lost her virginity to
Dealing with depression, possible survivor's guilt, and alienation, Madotsuki ended up befriending Masada, a cat-loving (he glides forward when Madotsuki uses the Cat effect) pianist and fellow outcast (he's an "alien"). Madotsuki frequently spent the night at his house, and eventually the two decided to sleep together. Madotsuki thought she was ready, but ended up deeply traumatized by the event (Kyuu Kyuu-Kun, while weird-looking, doesn't really seem all that malevolent, but then you go to the next area...).

If Masada is from Mars, then his Martian heritage explains his Cesare-like appearance.
Of course, just because someone accidentally crashes someplace doesn't mean they're from that place. That's like saying all the pilots and sailors who crashed their airplanes and ships into the Bermuda Triangle are actually from the Bermuda Triangle. But if the planet Masada crashed onto is Mars, his home planet, then his Martian heritage explains...
 * His skin color. Little sunlight reaches through Mar's dust-filled atmosphere, explaining Masada's extremely pale skin. In Earth's areas with little sunlight, the residents generally need to have lightly-pigmented skin in order to absorb enough Vitamin D.
 * His clothing. Mars is a cold planet compared to Earth. Masada's bodysuit is black because black is the color that absorbs the most wavelengths of electromagnetic radition (aka sunlight). The more electromagnetic radiation an object absorbs, the warmer it gets since the energy from electromagnetic radiation turns into thermal energy. And Masada is wearing a black bodysuit of all things since it keeps in the most body heat. Similarly on Earth, humans wear tight black wetsuits to keep warm when diving in cold water.
 * His hair color. As explained in the previous example, darker colors absorb more sunlight, leading to more thermal energy. Because Mars is so cold, dark-pigmented hair was the preferred evolutionary trait for Martians in attempt to stay warmer.
 * His eyes. Mars frequently has dust storms. Creatures on Earth who live in areas with lots of dust storms (such as deserts) have evolved adaptations to protect their eyes. While not exactly hollow a la Cesare, Masada's weird eyes with exotropia and grey sclerae are just what Martians' evolutionary adaptation to Mars's dust storms look like.
 * His tall and thin stature. Mars has approximately 40% the gravity that Earth does. On voyages to space, astronauts' spines lengthen due to the lack of Earth-like gravity to compact the spinal columns to their regular size. Because Mars has less gravity than Earth, Masada and other Martians can grow to be taller and thinner than Earthlings.
 * His blood?? As mentioned earlier, Mars is extremely cold. How can one so skinny like Masada live on Mars and not immediately freeze to death? Well, Martian blood has antifreeze-like proteins to prevent freezing. Many creatures on Earth that live in areas with Arctic climates such as fish and insects have antifreeze proteins in their blood to prevent them from freezing.

So that's my theory with the supporting details. Feel free to edit this if my science behind this does not contain good enough research.

Madotsuki, Mafurako, and Kamakurako are triplets
They look very similar, with Mafurako also being a closed-eyed brunette, and Kamakurako looking almost exactly like Madotsuki when she uses the long hair effect.
 * Kamakurako sleeps in an igloo, which is a snowy place, Mafurako is dressed for snowy weather, and Madotsuki can be dressed for snowy weather after finding the hat-and-scarf effect, and can use Yuki-onna for snowy weather as well.

Yuki-onna is Madotsuki's mother
This is mainly following the theory that Madotsuki, Mafurako, and Kamakurako are triplets, they are all related to snowy weather in some way or another, and so maybe Yuki-onna was their mother, considering she is also snowy weather related. She could also be a non-triplet sister, but since she doesn't look that much like them, her being a Mother would make more sense.

Uboa is the Earth
I had an image ready, but it will not let me share. Anyways, basically, just Google a picture of Uboa and a picture of the Earth turned mildly more left than normal in pictures, compare them, and you should see it.

Poniko gave birth to a demon child named Uboa, who's father is Masada the incubus
Masada and Uboa look so similar because they are Father and Daughter, and Uboa is a demon child birthed by Poniko.

Poniko is black
Poniko was a black girl living in a world of light-skinned people, so she decided to try skin bleaching. The skin bleach not making much of a difference, she tried real bleach. It messed up her face(Uboa), and she screamed(AAAAAAAAAAAAAAAA) and cried(the blue eyes could actually be tears, if this theory is true, although the theory could be true without this). The reason her skin is pale now is because, after the incident, she switched to using light concealer.

Uboa represents a rapist
Going along with the theory that the main character was raped, Uboa could represent the rapist. The house that Uboa appears in is actually the main character's living room. One day, when she came home, she went over to the light switches to fiddle with it a bit when suddenly, she got attacked by 'Uboa'. To add to this, the main character refuses to leave her room because it leads to the living room, where she was raped.

Uboa has a harelip.
Compare Uboa's mouth to the mouth of a harelipped child.

The Toriningen are birds that are angry at Madotsuki a la Angry Birds.
They chase and capture Madotsuki as revenge for her taking their eggs, otherwise known as "effects." The "sane" Toriningen originally don't realize that Madotsuki is the culprit behind their stolen eggs. However, they quickly change their mind and join their "insane" brethren if Madotsuki reveals her unsavory nature by stabbing them.

Madotsuki is Boo in the future.
Boo's traumatic early childhood would explain her troubled dreams. The doors would explain the Nexus.

The Game is one whole long nightmare dreamed up by A little girl.
Madotsuki is her alter ego, or maybe how she see's herself, And the name Madotsuki means 'Window' as in Madotsuki is her host body, her 'Window' into the dream world, the proposed 'real world' is not real at all, noting the surreal skys you see in everytime you walk onto the balcony, and Madotsuki's dreams are merely dreams within dreams. All of the nightmarish imagery are probably the consequences of watching a scary movie with terribly over the top scary scenes.

Madotsuki is accessing a world made of people's dreams, somewhat like Fantastica. The people she meets are some of the few who either still dream, or are still alive.
Dreams are rarely as persistent as the world Madotsuki visits again and again. Such a large and consistent world, though twisted and bizarre, seems more than just the product of her dreaming mind.

Yume Nikki was made with the AFGNCAAP gamer in mind.
The beauty of this game is how one can easily form a life story by giving their own meanings to the various imagery within Madotsuki.

With the exploration and the fact that different people think differently, Madotsuki can truly become "your character".

The game takes place in the 80s.
Madotsuki's TV is old, and she only has a Famicom.

Something even worse than the dreams is going on in the real world
The evidence is Madotsuki's reaction if you try to open the door in the real world - she shakes her head. It seems that she has no trouble with any of the creepy inhabitants of her dreams, but she doesn't want to face whatever's going on in the real world.
 * And note that the TV in her (real-world) room shows nothing but a test pattern. What is happening with all the transmitters in the world? This Troper believes that the game takes place After the End, where most of Earth has been destroyed by some terrible cataclysm, and Madotsuki does not want to live in a barren, barely inhabited world. She does not leave her room because of what's beyond the door - the horribly charred corpses of her family, a horde of zombies, etc.
 * Notice also the rather barren-looking landscape that is visible from the balcony.
 * And the fact that there is no building behind her balcony? The entire building- some kind of tower if the view is to be believed- is no wider than her room. That's just wrong.
 * That makes me realize something: Perhaps she doesn't want to leave her room because if she did she would plummet to her doom. The reason she jumped off the balcony is that she thought she was still dreaming.

Madotsuki is not in Japan.
Evident that in Japanese culture, it is always custom to take off one's shoes before entering a house. And Madotsuki always has shoes on.
 * There are a pair of 'indoor' slippers waiting outside on the balcony, so maybe Mado just doesn't bother with custom - she is a bit weird, after all. The currency in the game is yen, and there are strong elements of Japanese culture all over her dreams, so she's obviously associated with Japan. I don't think Mado herself is Japanese though, given that she has brown hair and looks much pinker than Monoko, Monoe and Seccom-Masada. Maybe she's a white person living in Japan? I hear Russians are quite common in Hokkaido.

Madotsuki lives in a crazy, mixed-up Fantasy World.
The room is her dream. In her dreams, the door fills her with fear, of things that have happened in her nightmares. Nothing in the real world can do anything worse than knock her out, and safety measures mean that anyone who is unconscious is immediately transported to their home, so they can be not-lost and fed or watered as necessary. Madotsuki is taking advantage of that by using some sort of Vulcan Death Grip Pinch to knock herself out and save the effort of going home under her own power. Some things scare her enough that she faints, instead of waking up as players assume. The end of the game is her trying to find a way to escape the room in her recurring dream without having to go through the door.

All of the dream world is based on Madotsuki's memories
My first thought came when I was reading a thread about Yume Nikki mass guessing on the forums where someone mentioned that area in the Number World with the calm Toriningen, the beds, and the closets. If anyone can recall that certain room that's guarded by a green...monster, I guess, that's in the upper left corner of the Number World (if I even remember correctly), it is filled with a bunch of those purple-ish monsters that have a single eye on them. Connecting this with AC's theory about that room with the Toriningen being like an orphanage, the "Killing Room" I'll call it, might have been connected to her childhood as well. If I can recall, the room was guarded by a green thing and the inside consisted of only the purple, moving things along with that one blue face on the floor. As far as my imagination go and piecing together some other ideas in my mind; that could have been the site of a rape and/or mass murder area, similar to the Wineville Chicken Coop Murders. The blue face on the floor was most likely the rapist/murderer, whom was defeated by Madotsuki stealing his weapon and using it against him in her own defense. She could have been afraid of the other victims or just plain whacked up already because by the time she realized what was going on, Madotsuki has stabbed and killed all of the people in that room. Soon she fled the area, looking around and killing people she got overly close to(Poniko, Masada, etc.) but then accidentally slipped up and got caught by the police after the incident represented by the dead (male) corpse that you get the stoplight effect from. This then explains why she was running from the Toriningens and why they locked her up in an inescapable place which is similar to a jail cell. She grew older while spending most of her life running, but finally found shelter in a small apartment room, probably in the middle of no where. It is a clear explanation to why she refuses to go outside, since she doesn't want to be caught by the police and questioned of the murders, possibly to the point of receiving beatings. But hey, it's just Wild Mass Guessing, right?

All the dream worlds are distorted representations of places and things she knows in her real life.
The Forest World is a road she usually travels by bus, the Block World is her school, the White Desert is the first complex dream-world she ever developed and is based on her childhood doodles and pen-drawings (white paper, black ink, nothing else), the Neon World is a video arcade, the numbers world is a train or subway station, and so on. (I haven't played it in awhile, that's all I remember immediately.)
 * I think the subway world is the subway system- note the vague people that do some sort of dance in the background while you walk- and that the numbers world is her opinion of computers or mathematics- but yeah, this works pretty well...
 * This one is a bit out there, but notice the sound Uboa makes. Maybe she went to the last World Cup and got mixed up in a crowd. Uboa's face would have been someone's painted-up face while the sound it makes would be the ever-present (at the time) vuvuzuelas.

Yume Nikki is but one of Kikiyama's dream
My theory is that the guy was once depressed and had this really scary dream, and he couldn't explain any of the stuff that happened in the dream, so he wrote it all in his diary before he forgot it. People gave him different interpretations to his dreams, which he didn't like completely. He kept getting other meaningless dreams, which he also compiled in a twisted storyline with no base. He turned his dreams into a game, in hopes that an extremely savvy bunch once joined forces to unravel the meanings of it all, if there ever was one.

Yume Nikki is but one of Kikiyama's trap
Alternately to the other above, Kikiyama never got any specific reason to do the game. He just wanted to mess with the minds of people by making a game with no background storyline, and full of different details that could be interpreted differently by people that suffered different traumas (Like blood. People always make a big fuss around blood, but not all the same way). As long as no answer was good enough, he'd be happy to know the game was scaring people enough while leaving them clueless. This page shows that people are trying to unravel a mystery that never existed, thus, being proof that they got severely affected by the game and want to know the reasoning behind several points in it. If you agreed even in the slightest to any of the above theories, then you have fallen for his trap too.

NASU is a metaphor for Just One More Level, turned Up to Eleven like many of the other things in Yume Nikki.
Because some versions of the game have a glitch that makes it impossible to leave NASU without exiting Yume Nikki, but it's also an Interface Screw because it's so freakin' addictive for such a simple game-within-a-game.

Yume Nikki actually takes place in a Sugar Bowl in disguise.
Sure it looks creepy and weird to us, but it's not as bad as it looks. There's never any real danger, just some strange scenery and teleportation. Many of the residents, from Masada-sensei to those people in the desert town make happy little noises when you talk to them - the Neon World in particular is even a perpetual party! Masada-sensei looks alone, but he has two chairs set at the table, like he's expecting a guest. Even when he crash lands, UFOs can be summoned - probably his friends to rescue him. The Toriningen? Just playing tag with Madotsuki, sending her to "base" when she gets tagged. Monoe and Kyukuy-kun smile at seeing you, and Monoko dances and spins when you talk to her in her true form. Even Uboa always has a smile on her face (though she looks bemused when you run into her, for good reason) and never tries to hurt Madotsuki; if not that, then Uboa could be Poniko with a costume to give Madotsuki a safe scare. Of course, Madotsuki could be something of a Nightmare Fuel Station Attendant because of the bloodier aspects, but such is in the eye of the beholder, right?.
 * It's like the opposite of a Crap Saccharine World.
 * Uboa's a girl?
 * There's a good chance, so this troper thought it made sense that Poniko would turn into/be replaced by another female while writing the original.

The whole White Desert is about pregnancy anomalies.
Just think about it: it is entirely monochrome (like a sonography) and the only red parts are reminiscent of veins or umbilical cords. Dave Spector has a big head, like a fetus in its first stages. Monoe is a vanishing twin, which explains why she "vanishes" when you interact with her. Also, her eyes, look like Takofuusen's, who is a reference to TRAP syndrome. Monoko is the product of two ischiopagi, like Lakshmi Tatma she has extra limbs. Connecting this with the rape theory, it's possible that Madotsuki searched information about pregnancy after she was raped, then she found out about these problems and she freaked out completely.

Every single theory is true and interconnected, but with a slight twist...
Well, this is quite obviously going to get a bit crazy, but just hear me out. So, Madotsuki is an insane, depressed young tranny (tomboy / intersexed individual / insert unusual gender-related issue-thing here) dealing with being raped while suffering through puberty in a post-apocalyptic world.

...No, wait! Come back! I swear it gets better! Alright, so she (he? For the sake of argument, we'll stick with she) is going through life as usual (y'know, the whole "not gonna go outside" thing, the dreaming, bemoaning her terrible life) when she comes to the conclusion that the only way to "fix" everything is to go back in time and alter her future by both killing her rapist and acting as a new friend for herself so younger Madotsuki won't be so depressingly lonely. She realizes, however, that she probably cannot allow her younger self to know who she is, she decides to disguise herself as an attractive young blonde woman under the name "Poniko", believing that if she disguises herself as someone she would find attractive (yes, she's a lesbian), she'd be more likely to form a friendship with her.

She goes back in time to her old school, only to see herself from a year or so (perhaps a few months) ago socializing with Monoe and her younger sister Monoko, two girls she suddenly remembers from her childhood. Recalling the tragic chain of events leading up Monoko's death at the hands of a speeding driver, causing Monoe to run away, never being found, Madotsuki (A.K.A. "Poniko") rushes over and introduces herself to the trio, hoping to befriend them all and hopefully prevent Monoko from getting killed. They all become close friends, hanging out all the time and sharing some of their best moments together. They even enroll in a piano class together, the four of them becoming very fond of their teacher, a sentimental young man named Komuro "Michael" (as his pale skin, hair and ability to moonwalk flawlessly reminded many of Michael Jackson) Sakamoto Dada Sensei, often called Masada-Sensei. He cared for the girls as if he was their older brother, becoming an honorary fifth member of their "clique". Other than the girls, his biggest pleasure (not like that you pervs D:<) in life was the piano. That and drugs, of course. One day, he crashed, leading to him getting fired, causing him to fall into a deep depression. He withdrew himself, shutting himself in his house and locking out all outside life. Madotsuki and "Poniko", wanting to cheer up their friend and teacher, tried to go to his place and do something for him. Unfortunely, they ended up getting lost in a dark forest near his house, where they encountered and seemingly friendly man offering them colorful candy if they let him "rub" them. After their refusual, he turned violent (as indicated by the menacing and somewhat phallic expression on his face), attacking and raping Madotsuki. "Poniko" tried helping before the man pulled out a knife and slashed at her, creating a deep wound on her abdomen (which she covered up with heavy turtleneck sweaters from that day forth). Madotsuki managed to yell out "Run Poniko, save yourself!" before the man slit her throat and left her in the forest to die.

Frantic, "Poniko" found the man's car, with the key still in the ignition, and drove off, going as fast as possible, eventually losing him but driving on out of fear and guilt. Accidentally running a red light, she doesn't notice Monoe and Monoko speaking with Masada-Sensei and his gay lover, the girls (and his lover) somehow having managed to get Masada out of his house. Poniko plows through Monoko and Masada's lover, freaking out Monoe and Masada-Sensei. Jumping out of the car, "Poniko" notices the body, taking in the bones sticking out of Monoko's arms, the pool of blood and brain matter around her head, the trail of drool hanging out of her mouth and the single tear gliding down her pale face. Looking to her friends, her heart sinks as Monoe's ever-present smile fades as she runs off (disappears). Masada locks himself up in his house once more, the once tenacious, outgoing man becoming silent and gloomy. "Poniko", now harboring an intense hatred for herself, goes home and kills herself. Madotsuki, barely alive, manages to go home and treat her wounds, healing completely but still emotionally and mentally disturbed from both the even and the news of Monoko's death, Monoe's disappearance and Masada's self-induced seclusion. She decides to go to "Poniko's" house for support. Noticing how, for whatever reason, "Poniko's" house looked especially peaceful that day, Mado enters using the key she had made, only to discover her friend half dead on the floor, smiling intently at Mado, who responds by recoiling in terror. "Poniko", who had failed in killing herself... somehow... shuffles over to Madotsuki and begins babbling incoherently about Cuban revolutionaries before confessing her love to Madotsuki and asking her to "join her", saying it will "ease the pain". Madotsuki admits to loving "Poniko" back, but states that she is confused as to what joining her would entail. Without warning, "Poniko" attacks Mado, who manages to escape the other girl's violence before watching her fall to the floor and die, her blood and vomit contrasting with the upbeat, girly interior of her home. The sun sets, giving the scene an eerie quality that sends Mado running home, where she pulls a Masada-Sensei and locks herself in her room, never leaving. After a while, she begins having odd dreams representing the events of her life, before finally choosing to end it all by jumping off of the balcony to commit suicide. Unfortunately for her, she finds out that she was still dreaming (although the events prior, as in Monoko's death and it's causes were real) and decides to take action, going back in time both to clear her mind (and dreams) and to right the wrongs caused by the well meaning "Poniko", all while dressed as her so it as if she is correcting her own wrongs.


 * This theory ties in with many other aspects of the game, but I can't list them all here (too lazy, not enough space), so feel free to PM me for the rest if you feel like it. Also, sorry if it's too... well, stupid.

Certain things Madotsuki finds in her dreams aren't native of her mindworld.
This explains the Mesoamerican-looking entities' presence in her dreams despite Madotsuki being a Japanese Hikikomori (it is unlikely she knows much about Mesoamerican cultures unless she has Internet or a bookshelf, but we don't see these in her room). Those entities are spirits and demons that found it confortable inside her disturbed psyche and are responsible for some of her problems. These demons are so powerful that Madotsuki´s censors are unable to kick them out from her system, only managing to imprison them in dark corners of her mind (the Aztec Rave Monkey for instance is trapped inside a small box and can only be seen when Madotsuki takes a peek in it, though parts of it are sealed in the background, along with the other Mayincatec invaders). Over time, these entities would break free and materialize in physical form thanks to their nourishment of negative emotions (which Madotsuki offers in heaping amounts) and prove a great threat towards the world. Madotsuki doesn't know this, but her room has actually been perfectly replicated inside a containment facility at the SCP Foundation in case these demons manage to escape.

The game was never meant to be this cryptic or subject to interpretation.
The current release of the game is 0.10, meaning it's not even close to finished (and at this point, likely won't ever be). It's possible Kikiyama originally planned to add context, backstory, dialogue, etc. that would have Jossed 99% of this page, but only got as far as a very elaborate tech demo before abandoning the project. YMMV on whether or not this is for the best.

NASU is a cursed video game.
It infects whoever plays it and catches 1 eggplant with a "mental virus" that fills their mind with insanity, fear and distortions of life as we know it, the only way to save oneself being to either ensuring someone else plays it and wins, or winning again a total of 1000000 times in a row. The creator of NASU, who accidentally somehow unleashed an evil, mind-destroying force needed a container to lock it in. She/He purposely made it depressingly futile so the virus wouldn't spread.

Madotsuki was already an abused, isolated child. Being raped by Poniko, who she thought was her friend was the straw that broke the camel's back. She shut it all out with simple videogames. She came across NASU one day. Suddenly, Madotsuki's mind became infected, and she passed out. When she woke up, she wanted to go downstairs, but a feeling of dread at the thought washed over her, and she couldn't bring herself to leave her room. She decided to go back to sleep, thinking that she'd just woken up too early. She was greeted by a distorted, abstract nightmare of her own life. She wakes up again, and plays NASU one more time to calm down. She loses, because You Suck at NASU.

She still can't force herself to leave her room out of fear of something she can't name, and keeps sleeping, hoping that she'll feel better. She eventually realizes this is pointless, and her crazy nightmares aren't helping. She decides to end it all and jumps off her balcony, killing herself. The jellyfish symbolize how NASU will always exist in the Yume Nikki world, destroying the minds of gamers everywhere.

Maybe Yume Nikki is also a cursed videogame and anyone who finds every secret, every detail and has won NASU at least 3 consecutive times is doomed. D:

"Yume Nikki" is an Alice In Wonderland fanwork.
Madotsuki, however, is already a very creative and strange girl. When she, she went into "Wonderland" with even more absurdities than her dreams. The  is simply tea that Madotsuki accidentally spilled during a party with the Mad Hatter and co. Jellyfish seem to be attracted to the ingredients.

The entire game is an allegory of life.
Looking at Yume Nikki in a bigger-picture sense, Madotsuki represents people, and her entire dream represents life. In life, we meet many things we cannot understand, and see many things we don't want to see. We meet strange people, most of who could disappear with no real impact on our lives, and most of which we will never interact with further than simply seeing them. The dream, like our life, lacks a straightforward purpose set forth by some greater being. In Madotsuki's dream and in life, materialistic possessions are absolutely required to progress to certain heights. With no spelled out purpose, gathering possessions quickly becomes the main goal, as they open up doorways to what one believes may be the truth. However, in the end, the truth is not found, even after gathering all the objects possible. The world is just as confusing and purposeless as before. And then we die.

Madotsuki's room represents humanity's selfish nature. Nothing matters outside of our own little world, and we refuse to care about things not affecting us. The Dream world shows this, in that barely anyone interacts with each other unless provoked.

Kikiyama is/was an introverted, bullied 13-year old girl, and Madotsuki is a self-insert.
A lot of the effects could stem from teasing over things like weight, appearance and hair length/color. Some of them even seem to come from Japanese folk tales, or activities done over the seasons (bicycle, hat and scarf, etc).

There was one more effect that would've changed the ending.
Since Yume Nikki doesn't seem to be finished (heck, KIKIYAMA even said it's not done and would be updated, though there's no way to tell when), it wasn't attainable. The Downer Ending was simply the "bad ending" that happened when you didn't attain certain conditions.

This isn't JUST Madotsuki's dreams.
She's somehow sharing the same dream with a myriad of other individuals. Poniko is another hikikomori who refuses to leave her home, Masada is a troubled man who wants to escape to another world, whether or not he "crash lands", Monoe is a depressed girl who puts on an almost-smile for everyone until she finally fades away, Monoko is an insecure girl who sees herself as a disgusting monster. Their dreams all somehow mashed together, and this is the end result.

Yume Nikki is an ameteur horror story written by an actual girl, Madotsuki, who is known as Kikiyama on the internet.
She's challenged herself to write a horror story with a new chapter every night. As a child, she has homework, chores and other responsibilities to tend to, however. So, she's locked herself in her room and vows never to leave her room until the story is finally finished. The effects are large parts that she plans to incorporate into her story. When you collect all the effects, she realizes that there is literally no end to the story, and her mind will keep on generating horrifying creatures. Her life literally HAS become the story in itself. She halts the original plot, and rewrites it as a dream diary.

She couldn't get the story published, as she is a kid, so she made use of RPG Maker and released a game adaption for free. This also explains the gameplay. Kikiyama/Madotsuki probably isn't interested in making an RPG, she just wants the story made public. Yes, Kikiyama is a girl.

This isn't Madotsuki's dream
The fact that most of the Effects have limited if any use is because they were never meant for Madostuki. Rather, this Madostuki is just a dream avatar of the now-dead real Madotsuki, Madowanki, inside of another character's dream, most likely Shitai. Madowanki went Yandere on his ass, culminating in a traffic accident that killed all the characters except for Shitai, who is not active in the dream world like the other dead avatars because he's still on a lifeline. In a perpetual nightmare for the comatose Shitai, each avatar would collect Effects that had something to do with them, events would play out in a stylized manner, ending with Shitai dead and all the dreamscape reset. For whatever reason, this incarnation of Madowanki, Madotsuki, gained some degree of sentience and became The Ishmael. She has no idea what's going on at first, and uses the Dreamscape as an escape from her waiting area in limbo.

As the game goes on, she finds the other avatars and Effects and realizes just what's happening. The final piece she realizes is that she doesn't exist, and that by collecting the 24 Effects and putting them out of reach of the avatars she has stalled the nightmare indefinately. In order to break it, she realizes, the illusion of the girl Madotsuki is the only avatar that can erase itself in an unplanned way.

At the end of the game, Shitai wakes up and forgives her.

Madotsuki and her dreams are but a representation of everyone's insecurities
Madotsuki represents every individual in society, or mor elikely their insecurities, without any of the facades they put out. She's a Hikkikomori, which represents our true selves locked deep inside us, the only way to get out is when sleeping. When we sleep we contact our unconcious, maybe for Madotsuki it's the opposite, it's her only way or reaching our concious. She explores the dreamworld, which is an abstract representation of the most common insecurities and desires, the effects are also a clear representation of what we wish and what we fear.

The bicycle are our material desires, the flute our want to have some kind of talent, the hat and scarf, long hair and blonde hair are our superficial wants, however, fat, midget and poo hair are the things we don't like about our aspect, same as frog, the witch is how we feel of our attitude (And how we feel better if we throw away our caring and just fly). Knife effect is our inner desires, our darkest wishes, or simply the hate we have to society. Stoplight, ghost or nopperabu are our fears of dying in any way.

The NPCs also support this: Poniko is our ideal as a person, the perfect being we want to be, however we are unable to fully reach out to it, thus we start hating it, becoming slowly corrupted, thus Uboa. Monoko is what we fear of us happening, the fear of accident, death or phisical pain. Masada is the people who accept theirselves and all their defects (Thus the googly eyes), they seem far away from us, but they live happy, peacefully. Toriningen are the people who judge us, some of them silently and other's more aggresively. Zones like the refugee camp, FACE, and etc. are representation of common social fears: The fear of being poor, the fear of growing up, the fear of being abused in any way, etc.

In the end, when we collect all the effects and drop them in the entrance (The connection between unconcius and concius) we are allowed to go further. In other words, when we drop our insecurities and the desires they create and accept ourselves, Madotsuki, the representation of our insecurity, dies, fades away. It's represented as commiting suicide because Madotsuki is part of us, and we kill her, she kills herself. The bloodstain is shaped as a keyhole to give a message to the person who finally killed Madotsuki, they are free, free from judgement and free to embrace themselves without fear or without feeling guilty

Kikiyama killed him/herself and Yume Nikki is his/her suicide note.
Kikiyama's website has not been updated for a year and a half; YN's changelog states that it hasn't been updated since October 2007. Kikiyama, a depressed individual, created the game as a metaphor for his/her daily existence and released it onto the internet as a sort of cry for help. Eventually, the pain became unbearable and he committed suicide before he could fully finish the game.
 * Kikiyama is still alive, he responds to E-Mails (if I'd get a cent every time I read that...).

there is no hidden symbolism in Yume Nikki. The author simply based it on his/her own dreams.
As far as portraying dreams in fiction goes, Yume Nikki is one of the most accurate ones. The dreamscapes shown are very close to actual dreams, so it's not entirely unlikely that they are based on real dreams. In fact, low pixel count notwithstanding, they can easily pass as such.
 * Maybe I'm the weird one, but aren't most people's dreams less like a surrealistic adventure through an abstract horrorscape, and more like a screwed-up, nonsensical version of their waking lives? Your Mileage May Vary quite a bit on this one.

The dreams are not just Madotsuki's - they're a shared dream world that few can control, and she just happens to be able to do so.
The dreams Madotsuki has are NOT her own personal dreams - they are another, alternate world that is accessible only while sleeping, and where people have avatars they inhabit - sometimes with very, very odd appearances. Dying in the dream world simply wakes the person up in the real world, nobody actually is killed in Yume Nikki - however, dying in the dream world DOES hurt, and the screaming heard when Madotsuki kills someone in dream is a mixture of a cry of pain and a cry of fear as the person wakes up. In reality, the dream world is available to all people in the Yume Nikki universe, but not everyone can control some aspects of the world. Those that cannot appear as Toriningen, the number people, the weird demons on the train, etc. Madotsuki and some of the other prominent characters from various events are of the few in this group who can do so.
 * Madotsuki can control the dream world only through the effects, and only she can speak to certain people who can also use those effects. By doing so, she can use the effects as well; in this way she is an "Uber" in the sense that she can easily shift to be anything she wants to be in the dream world. Others, such as the Toriningen, do not have this privilege, and that makes some of them very angry - they send Madotsuki to the inescapable areas out of jealousy over her ability to do so much more in the dream world than they can. Some, however, are friendly and fine with it until you try to harm them, in which case they rightfully become angry and imprison Madotsuki. Madotsuki spends so much time in this dream world she forgets what reality is, so when she wakes up she decides to "wake up" by killing herself, as she would in the dream world. It... doesn't work.
 * Monoko can control the dream world as well, but her avatar in the dream realm is a monstrous, mutated being with multiple arms. She can change how things look at will, but not her appearance, and tends to hang out in the White Desert because that is the only place she looks like a 'normal' person and others don't freak out over her... unusual appearance. She is somewhat ashamed of how she looks in the dream, you see. However, when Madotsuki uses the stoplight effect on her and gets close to her, Monoko's camouflage fails and when Madotsuki approaches her, she becomes angry and jumps and spins around to show her displeasure at being 'found out' in her avatar's true form.
 * Monoe is the sister of Monoko, and her ability in the dream realm is to make things appear or disappear at will. She can also do so to herself. In fact, she likes to play "keep-away" with other dreamers this way. So, when Madotsuki approaches her, Monoe smirks (or smiles, your choice) and fades out, then moves elsewhere and fades back in. In this way she and Madotsuki are actually playing a game, which ends only when one or the other becomes bored with the game - usually Madotsuki first.
 * Masada can control sound and music in the dream realm, and also has an interest in astronomy, thus he pilots a spaceship with a keyboard in it. He is a nice man and often brings other dreamers on trips with him into Dream Outer Space, but he has a terrible phobia of knives which carries over from the real world to the dream realm. This is why he will react favorably to Madotsuki until she wields a knife, in which case he backs away fearfully. While other dreamers do this (because they don't want to die and thus wake up), Masada is actually scared of the knife itself. Upon the ship "crashing", Masada is gone. This is because he has died in the dream and gone back to the real world, hence he is not there. Upon returning to dream he will have to re-imagine his space ship, since there is no permanence of objects in dream due to its ephemeral state.
 * Now the big one - Poniko/Uboa. Poniko is actually a normal girl like Madotsuki, but she has an... interesting ability - she can teleport herself, others, and objects elsewhere in dream. However, she can only do this by shifting to her alternate dream form - the distorted, frightening looking Uboa. Poniko likes to play tricks on others by shifting into Uboa and spooking people, or sneaking up on them and transporting them elsewhere. It helps that as Uboa, she can also emit a deafening, scary noise if she chooses (one that sounds an awful lot like "AAAAAAAAAAAAAAAAAA" and naturally spooks people), which scares people more, and which Poniko finds hilarious. In the case of Madotsuki and the lightswitch, however, the case is simple - Poniko is annoyed with Madotsuki for turning the lights on and off. You see, she was in the middle of doing something and needed the lights on at the time, and the flickering of the lights doesn't help. So Poniko becomes angry and turns into Uboa to spook Madotsuki and teach her a lesson. She also mentally manipulates the lock on the door to spook her more. However, she does nothing unless Madotsuki touches her, because... well, Nothing Is Scarier. If Madotsuki touches Poniko when she is Uboa, Poniko becomes even more upset and transports Madotsuki to a spooky world she can't leave without waking up, hence the upset-looking face Uboa has when you touch it.
 * Various other characters appear differently, such as the weird monsters with the nubs you hit to make them vomit blood, or the Octopus balloon thing in the White Desert. This is simply how various people manifest in the dream world.
 * Anyone else feeling like making a RP forum out of this?

The Dream World is the reality, when Madotsuki is "awake", she's in an self induced trance/sleep.
The world she lives in is terrifying. In order to escape, she acquires some sort of thing that lets her knock herself out by pinching her cheek. She dreams of a "normal" world, but she can't go outside because the only places she's ever seen that aren't like the rest of the horror-filled world are her room and balcony. She has some sort of unseen protector who takes her back to her balcony whenever she goes to sleep. Perhaps this protector is Uboa, who appears when she turns the lights of in Poniko's house because Poniko is not what she seems and switching the lights might enrage her. It takes Madotsuki to a place so horrific and inescapable that she's forced to use her escape method. The effects are tools she collects to survive outside of her room. When she's abandoned her effects at the end, she's decided to commit suicide. She kills her dreamself, and when the background fades and the jellyfish appear it's her alternate reality fading away. She, having abandoned her tools of self preservation, was killed by monsters in reality before her protector could get to her.

Continuation of shared dreams theory...
Many people actually have the ability to enter shared dream worlds. Each person has their own personal Nexus (think of it as a time lord and their TARDIS), with doors based off of their personalities, mental state, and interest. Madotsuki is... unhinged and thus has very disturbing dream worlds. Masada may have an interest in space travel and has a door leading to that realm.

The dreamers can meet up with each other if they have the same interests, and therefore, the same dream worlds. However, some dreamers can wander through their dreams and find doorways to different dream worlds. As a result, some unfortunate misfits manage to wander into Madotsuki's realms.

Plus, all of the dreamers can use Effects. Some of the distorted characters in the game are actually dreamers using effects. Monoko's hidden form is actually an effect, which Madotsuki's stoplight accidently triggers. This troper personally believes that this effect is an advanced form of the weird hand teleporting thingy effect that allows her to travel to multiple dream worlds.

And I agree, someone should make a roleplay or a fanfic on this.

Some aspects of Yume Nikki are subtly inspired by The Cabinet of Dr. Caligari.
Their shared aspects of Surreal Horror, Mind Screw, and bizarre settings aside, the character Masada also Looks Like Cesare. In Yume Nikki, Madotsuki can sleep in Masada's large white bed which is only accessible from its. In The Cabinet of Dr Caligari, the damsel Jane sleeps in a large white bed which Cesare approaches from its left. However there is one significant inversion from the original source material. Unlike Cesare, Masada doesn't creepily shamble around to stab individuals to death while he sleeps. Instead, creepy girl Madotsuki is the one who wanders around in her sleep/dreams to knife innocents.
 * In a certain area of the game we can find Madotsuki sleeping inside a wooden cabinet. Just as Cesare does.
 * Yume Nikki's White Desert area looks awfully similar to the bizarre scenery found in Caligari.
 * Like Cesare, Madotsuki knifes people in her sleep because the person remotely controlling her gets sick amusement from it. That person? The player.

Madotsuki is the dream-self of the protagonist in NASU.
Turning on NASU is actually Madotsuki waking up. She dreams her ideas of what it is like to be a human, distorted because as a (bird? Can't really tell with the graphics) she completely misunderstands human ritual and behavior. Once she's seen everything, Madotsuki

Madotsuki is living in the Dennou Coil universe
She's somehow getting pulled into the Coil domain when she sleeps (a similar thing happens in the show). Observe the similarities between the world behind purple door and the abandoned space in Dennou coil. The effects? Metabugs!

Madotsuki is actually one of Itoshiki Nozomu's students
I mean, just think about it; the Meaningful Name, the fact that she has a rather quirky personality + a bunch of psychological problems, just like all of Itoshiki's students (except, of course, for "normal girl" Nami Hitō), and just compare Monoko and Monoe with the girls in Itoshiki's class - the resemblance is uncanny. In fact, the presence of Monoko and Monoe in Madotsuki's dreams could very well be the result of memories of her classmates resurfacing in her dreams.

Madotsuki is the little sister of Brock from Pokémon
She's got both trademark traits of one of Brock's family members: Eyes Always Shut and brown hair. I think one of his sisters had braided hair, as well...

Madotsuki's mind is the second Matrix
Confounded by the fact that humanity couldn't accept a truly perfect world, the creators of the Matrix created a world based on the deepest insecurities, fears, hatreds and pains of a young girl with some kind of trauma in her past. However, the result wasn't pretty- only the original girl could deal with the traumatic world around her. The rest became mindless denizens of various parts of her mind, so traumatized by fear and sadness that they can now hardly think, let alone move, or became desperate to end their world by forcing her to wake up. Scattered throughout this new Matrix are beings who can impart some small bit of knowledge to her- the ability to change her form, bring death to others, and otherwise alter the world around her in small, significant ways. Only through the collection and rejection of these abilities- and symbolically, the rejection world they came from- can humanity be free again.
 * By causing instrumentality

Poniko is an Arrancar.
Most of the time she looks fairly normal, but if you piss her off too much she turns into a huge monster. Since said monster looks like a really messed up black-and-white face, there's a certain resemblance to a Hollow mask.

Uboa is the Devil's Machine.
The Devil's Machine is an eyeball with Ness's face on it, and  Sound familiar? Furthermore, the game is full of Earthbound shout outs, and what better honor than to include the game's iconic final boss?
 * Does this mean that Che Guevara is the Devil's Machine? Also, how is Uboa an eyeball with Ness's face on it?

Madotsuki, after committing suicide, is reborn as sinbound Haibane.

 * It actually makes a bit too much sense. Madotsuki is perfect Haibane material: not only did she die when she was young and, as you see above, rife with mental issues, she even commits suicide!

Uboa is Nyarlathotep
I know this is a current joke in the Wild Mass Guessing, but is make sense. One of Nyarly's avatar (The Haunter in the Dark) can possess people, but it reveal his real form in the darkness. To put it simple, Poniko is possessed by Nyarlathotep.
 * Does this mean that Che Guevara is Nyarlathotep?

Uboa is the father of Arakune.
Compare this to [[media:699190-arakune_large.jpg|this]]. She's suffering an existential crisis due to a recent trauma so she's trying to find herself via lucid dreaming or something. The aztec monkey that shows up in the background of a few areas is her spirit animal, and the creatures and worlds are all other aspects of her psyche; the 'graffiti world' is her artistic side, whereas the 'number world' is her mathematical side (since the number world seems to have more doors than the other worlds, this might mean that she's better at logic and math). The trauma might have been seeing someone she loved getting hit by a car (the dead body on the road), a rape (or alternatively, being raped and becoming pregnant), or having a fight with her friend that ended in her being attacked by that friend (Poniko turning into Uboa). At the end she doesn't like what she finds, so she commits suicide.

Madotsuki is Lain
After the events of Serial Experiments Lain, something corrupted her, causing erratic effects on the world. Determined to settle the issue, Lain changed her name to match a fake ID and locked herself in a rented room while she sorted things out. her dream world is an interpretation of the corrupted connections to the wired that requires fixing. When they were all fixed, she tested for proper connection by synthesizing a staircase on the balcony, which she used to initiate the changes (sort of like rebooting a computer.) and cease the erratic behavior in the real world. The true ending of the game is Madotsuki paying a months rent, and going on her way.

Madotsuki is Haruhi if Kyon had died
N-Now hear me out before dismissing this as another OMG HARUHI WMG... In an alternate continuity or somesuch,, and Haruhi becomes depressed and slightly insane. The dream-characters are her trying to reunite with her friends in a world where everything is "all right" again, but slowly her depression twists things around.
 * Monoko could be how she eventually sees Mikuru. A girl with a twisted, unnatural body, as opposed to the Moe light she used to be seen in.
 * Shitai is, of course, Kyon. Dead body with scraggly brown hair, found in a saddening area, etc.
 * Monoe is Yuki. Distant, seemingly benign, etc.
 * Itsuki is Masada. H-He just is.
 * And finally,

Madotsuki met The Grinch at some point, and cracked when he gave her a First Class Grinching. She relives the experience in her nightmares.
Because that one Mind Screw Surreal Horror scene from Halloween Is Grinch Night looks a lot like what would have happened if all the artwork in Yume Nikki was drawn by Dr. Seuss.
 * * snrk* ...I'm a horrible person for laughing at that . But it would fit with the rest of the WMGs that don't involve Poniko being Che Guevara in disguise.
 * Even better, at around 1:09 in that video, a creature that looks exactly like a winged version of the things in the sky on the road through the forest pops up.

Madotsuki is an E.V.O.
The effects you gather are her E.V.O abilities. The effects you haven't collected yet are actually abilities she possesses, but can't yet control. Need more proof? Look at Breach and Monoko.
 * Yesss I was waiting for someone to mention this.

The light switch in Poniko's house is an eversion point.
Well, it makes as much sense as anything else. Something perfectly innocent gets turned nightmarish by pressing a button in an otherwise innocent place... ... yeah, I got nothing.
 * Berserk Button?

Madotsuki is actually obsessed with Earthbound
The NASU game is her only other game, which came from the system. She is currently grounded because she played Earthbound too much, and that is why she won't leave the room ("I can't, or the game will be kept from me for another week!"). Eventually, this, let's say, month long grounding with nothing but NASU to play drives her insane, and she commits suicide. Her parents, of course, are shocked, and start convincing people to boycott Earthbound. Word of the boycott and the reason behind it reaches the states, and NoA decides that such an addictive game should never come to North America. The end result? We get stuck without an export because Madotsuki is an addict.

Yume Nikki is linked to the movie Inception
Many concepts from Inception, including dream/subconscious exploration and reality confusion, are comparable to directly assumable theories made about Yume Nikki. For example, Cobb's dream,  is parallel to Madotsuki's dream world, with the different doors. In addition, could be similar to the end of the game when Madotsuki, assuming Madotsuki had similar intentions. That last event in Yume Nikki can also be compared to when Ariadne and Fischer Jr. had to. The scenery on Madotsuki's balcony is also very similar to the aswell.
 * Wut? I just saw Inception, and I swear, I was JUST about to post this. Thanks for making me feel even more inadequate, tvtropes! But it's ok, because no theory can top this....

Madotsuki and Ness from Earthbound are somehow related

 * Ness is able to communicate telepathically.
 * Giygas is inspired by a rape scene... its dialogue in the final battle comes from a rape victim's point of view.
 * 1) ...Except that's not true. You Did Not Do the Research. See here: http://earthboundcentral.com/2010/01/clearing-up-some-myths/
 * There are obvious shoutouts to Earthbound in Yume Nikki
 * Assuming Madotsuki was raped (as there appears to be quite a bit of evidence suggesting that), and assuming some Earthbound WMGs are valid (Itoi himself said the final scene is open for any interpretation), Madotsuki was calling out to Ness telepathically, causing the final battle in Earthbound to take the form it did.
 * This brings another WMG to mind...

Giygas and Uboa are the same entity

 * This kind of backs up an earlier WMG about Poniko being the one who raped Madotsuki. Bear with this scenario for a minute...
 * Madotsuki and Poniko have been friends for a while... Madotsuki would always stay the night with Poniko... Until one night, when the lights went out, Poniko locked the door and became a monster in Madotsuki's eyes... trapping her... hence the realm Madotsuki is teleported to if you touch Uboa.
 * Uboa is how Madotsuki remembers the rape, and Giygas is how Madotsuki's vision came across to Ness.
 * 1) Nope. http://earthboundcentral.com/2010/01/clearing-up-some-myths/

== In addition to Che Guevara, a Time Lord, Nyarlathotep, the Devil's Machine, Masada, female, Poniko, Arakune's father, Monoe, Poniko's imaginary friends, Giygas, a Flying Mask and "hips", Uboa is also a Kernelsprite from Homestuck. == This is discussed over on Homestuck's WMG page.

Madotsuki is an Assassin.
Madotsuki is an assassin in training that Aspergo kidnapped for information regarding a Mayan Piece of Eden, but they find out too late that she is for some reason incompatable with the device. As a result of this, all her ancestor's memories overlap and mutate when she uses the machine. The Templars decide to let her continue to use the machine in the hope that they may still be able to gain some hint as to the artifact's location despite the incompatability. At the end of the game, she finally manages to gain enough knowledge from the bleeding effect to know how to do a leap of faith from the top of the building, landing in a bale of hay and walking away unharmed.
 * Corollary: Matdotsuki is the assassin who killed the notorious Templar Che Guevara.
 * Then what's with the pool of blood at the end?

Alice Human Sacrifice takes place in the Yume Nikki world.
Madotsuki's dreams aren't just "dreams", but a bizarre supernatural force that manifests in the minds of anyone with noticeable problems in life. Monoe and Monoko, who happen to be twins, are its very first victims, followed by Masada-sensei, then Dave Spector.

Poniko, like Madotsuki, kept a dream diary, which is the only reason she doesn't appear to be from the White Desert. However, Poniko also ripped up her dream diary before killing herself, creating a side effect in which she transforms against her own will from a pretty young blond to Uboa, who may belong in the White Desert, judging by its color scheme. On the other hand, Madotsuki keeps her diary til the very end. Monoko is horribly disfigured because she purposely killed herself too many times in her dreams instead of pinching herself. Monoe is her sister, but was smart enough to just pinch herself each time, so she only got a slightly Uncanny Valley face. Masada-sensei stared too long at FACE without blinking, so it ruined the look of his eyes in the dream. Dave Spector is just a celebrity that was there because everyone wanted him to be. When Madotsuki  and travels into Meiko, Rin and Len's (who are all hikkikomoris) minds with the rest of the characters.

Meiko is a violent girl who couldn't trust herself not to attack someone over the slightest thing, so she locks herself in her room and refuses to leave.

Kaito is a successful teen artist, but at his latest concert, two fans had attacked eachother over who loves him more. He blames himself and refuses to leave his room, let alone go out in public or even speak.

Miku is a girl who gets pushed about and baselessly flirted with because she's young-looking and short for her age. She loses control and kills a male who mocked her flat chest. After she sees what she's done, she can no longer bring herself to be among other humans.

Rin and Len are 10-year old siblings who are so close they share a bed (It's up to you whether or not this implies certain things). They shut out the rest of the world in return for their own intimacy.

Meiko kills everything in her dreams, as she either thinks they are threats to her, or she believes them to be twisted creations and she wants to eleminate them from her mind. She fails to kill some, however, and is teleported somewhere she can't escape without pinching herself and starting all over again.

Kaito wants to sing again, but is afraid to do it in the real world. His dream has a village full of people who have never heard music (apart from ah nata nee ah nata nee centimeter, of course). He unintentionally hypnotizes them with his singing voice. Like what happened in the real world, two of his fans go insane, but one of them accidentally shoots Kaito, waking him up immediately. He also has to start all over again.

As soon as Miku enters her dream world, she is hailed as a goddess and a queen. She starts her own country. She lives so happily in this dream that she refuses to wake up. But she is unable to forget what she had done in the real world, sees Uboa the moment she turns the light off in her royal chambers, then she wakes up crying and screaming. She still returns to her dream, but this happens over and over.

Rin and Len share their dreams. They explore strange, but positive worlds accessed through doors, similar to Madotsuki. They also keep a dream diary. They soon receive an invitation to the castle from the queen. They have no real desire to see her, but they go looking for the castle door nonetheless. They get distracted along the way and see a new, different door. They walk through it unknowingly, but the door slams behind them, trapping them in their dream wold as they're forced to explore Madotsuki's diary, AKA "Alice's Wonderland" unless they both wake up and kill themselves, then become part of the dream, like Madotsuki.

Madotsuki is Zoey after
With all the crossover theories in here, I decided to toss in my own, with all the ideas that Yume Nikki is set during some sort of apocalypse, which is quite likely. So for those that have played The Passing, we all know that the original Survivors were entirely devastated by, but especially Zoey. Fans believe this is because the two had a sort of father-daughter relationship and grew very close over time. So here's how I think this works: After meeting the second group of Survivors, the original Survivors eventually get off the bridge and find safety in a rural apartment safe room. (True, we do not see any other characters in the room in-game besides Madotsuki, but, considering this is Yume Nikki we're talking about, there could be invisible sprites there for all we know.) So, Zoey falls asleep and finds herself having a very odd dream. And here's what I think about the characters: Poniko represents Bill. Poniko seems to be a distant friend of Madotsuki's, which is what Bill is to Zoey now. Uboa most likely represents. Monoe and Monoko represent Francis and Louis, Monoko representing Louis, who injured his leg badly, and the extra limbs, bleeding eye and mouth, etc. might be caused by a fear of Zoey's that he may be hurt even more. Francis is Monoe because, although he does his best to help the situation, he seems to avoid the subject of and sometimes even tries to make light of it, along with Louis. Monoe simply disappears whenever you try to interact with her. As for Masada, he can represent either Ellis, from fan speculation that Masada and Madotsuki might have had a relationship at some previous point, and the fact that in The Passing, it's quite obvious that Ellis and Zoey have feelings for each other, or he could represent all of the Left 4 Dead 2 Survivors, who found great friendship in the original Survivors, but then had to leave them behind, and perhaps felt a little lonely without them, as Masada seems to feel lonely by himself. The Toriningen simply represent all of the other Infected, Common and Special, and the closed off area they send you to could be Zoey's idea of what happens after death. The reason for all of the characters besides Masada being female could be Zoey's want for more female friends, even though she is happy with the ones she has, and of course she and Rochelle are most likely the last two women on Earth. In her dream, Zoey is because of all that had happened, but in reality, this is only Louis and Francis waking her up from her sleep. I think I had some other theories, but I forgot them because I wasn't able to put them down immediately. I just wanted to toss in my idea.

Alice Human Sacrifice IS set in the Yume Nikki universe, but the people in Mado's dreams are the ALICEs, including Madotsuki herself.
Kamakurako is the first ALICE. As the story tells, she goes berserk and kills everything. The toriningen, or some other force capture her and trap her in the igloo. The sound of another creature, AKA Madotsuki's Cat Effect makes her shudder.

Masada is the second ALICE. His spaceship took him to many different worlds, spreading his enchanting piano music. One particular song, however ("Anata ni, anata ni, Sentimental" which means "Sentimental for you", translated) drove people mad. Instead of being shot and killed, he was stabbed numerous times, which explains how he runs whenever Mado brandishes a knife.

Poniko is the third ALICE. All the creatures in the land loved her very much, and even built her a little house and made her the Queen Of The Dreamland. Everything went well at first, but she slowly became more and more paranoid of these monsters. She realized that if they felt like rebelling, they could eat her, transport her to an inescapable place, or worse (remember, it's Yume Nikki, the videogame that WILL make you shit yourself in fear). Little by little, she starts to think that being as fearful and sinister as them will integrate her for good. When she sees Madotsuki, she assumes her to be normal, but how would you react if some random girl holding a knife turned your lights on and off? She thinks Madotsuki has come to kill her after conducting in some kind of light-on light-off ritual. She turns into Uboa, and transports Mado away. She will forever rule Dreamland as its queen.

Monoko and Monoe are the fourth ALICE. Together, they explore the Dreamland. They unknowingly stumble into Poniko's castle, and as luck would have it, the moment they turned off the light, Uboa greeted them. Instead of both being trapped in an inescapable place, they were each seperated, Monoe cast underground and Monoko thrown into the White Desert. Monoko goes mad from the vastness of the desert, and hallucinates her body changing to something monstrous when something she only sees in the real world, a stoplight is shown to her. Monoe feels empty without her sister and wants to disappear, so, she does just that. As the story tells, they are never woken from their deep dreaming, forever they wander in search of eachother in the Dreamland. Neither of them want anything to do with Madotsuki.

Madotsuki is the fifth and final ALICE. Unlike the other dream victims, and very lucky for her, Mado can switch between waking up and dreaming freely. However, to her own chagrin, her dreams drive her insane. In her confusion and fear, she. What she doesn't know, however, is that she was only dreaming of her bedroom, which is why there is suddenly a stepstone. She goes through the  of her own dreams, while in real life she is thought to be suffering from a coma. The jellyfish around the bloodstain represent that.

Basing in the After the End [WMG], Yume Nikki takes place After The End of Evangelion
The game begins a few time after Instrumentallity (maybe some days, weeks or even months) and Madotsuki is the only one that have returned to her own self in the whole town and even maybe just she, Shinji, Asuka and few other people have returned by that time. Because of her loneliness she gets depressed and shuts in. Monoko could have been actually the little sister of Monoe and could have actually died in car accident and for some reason Madotsuki feel guilty about that. Masada-sensei could have been actually Madotsuki's piano teacher. Monoe could really have been a friend of Madotsuki and her dissaparence is actually a representation when Monoe dissapear and get turned into LCL in front of Madotsuki's eyes when the Third Impact began. Maybe Poniko was actually Madotsuki's best friend that died during the attack of Zeruel when both were in Tokyo-3 ( seriously, just compare Uboa's face with Zeruel's face, they are very similar). This is how it happened: for some reason Madotsuki and Poniko traveled to Tokyo-3 (maybe a school trip or even a family trip). In one moment Madotsuki was calling to Poniko who was very distracted with something else but, suddenly, a giant explosion happened and there was a black out in the place where they were and Madotsuki begin to hear a lot of screams and laments and when she could finally see something, she saw Zeruel's face where Poniko was previously and this event is represented in Madotsuki's dream as the Uboa's event. And for all of those sexual interpretations, they doesn't really mean that, so Madotsuki is neither a female-to-male transexual, nor a male-to-female transexual, nor a lesbian and she never has been raped, the real reason of that is that her mind was corrupted when she was brain bleached, mind raped and mind screwed with Shinji's mind when he was in the middle of the Instrumentallity controlling the Third Impact and those things are actually reminiscences of Shinji's memories (also the Toriningen's face could be an interpretation of Shinji's memories about Sachiel's face and Kyuukyuu-kun could be also an interpretation too but of Shamshel(a pinkish phallic-looking creature)).

Konata is Madotsuki.
Konata is a lonely Japanese otaku. Her real name was never Madotsuki. She's bullied in school and has no friends. Her hair isn't extremely long, flowy and blue. It's a boring shade of brown in two normal braids. Her eyes aren't vibrant and green. They're dull and dark brown. Her life is so miserable, she can no longer face another day and just stays in her room with her anime and manga (if you paid attention throughout the game, you'd notice in her room is a glass case with a shelf filled with either books, films, or videogames, if not all those things). She gets hungry, so she just goes to sleep to weigh her growling stomach down. Her dreams trouble her with twisted allusions to her sad life of being bullied, ignored, insulted and hated ("Your face is all ugly and frog-like", "Your hair reminds me of shit", etc), her various desires (join the unreachable toriningen/popular kids party, colored/long hair, lose weight, etc) and her equally depressing home life with an equally miserable lolicon father who shares her pain of being "alone", except he was lucky enough to win the heart of a girl who previously disliked him, though this "prize" is cut short when she dies.

Lucky Star is what Konata's life would be like if she got her wish. Everyone just being crazy and silly, having fun and goofing around. Nobody bullying her for her interests, and she even has friends. In the final episode of Lucky Star, heck, even the OP, Konata is in the school cheerleading squad, which means she finally gets into the toriningen party! Remember this is all just her wish, and Yume Nikki is still the harsh reality, though.

Uboa is Poniko's Imaginary Friend.
Uboa is very shy and hides whenever visitors appear, but when Madotsuki keeps switching the lights on and off, Poniko gets frustrated. Uboa decides to do something about it (i.e. talk to Madotsuki in his own language consisting of "AAAAAAAAAAAA" that only Poniko can understand, though Uboa himself does not know this) and when Mado fails to reply, Uboa simply sends her away.

Madotsuki's real name is Tara Gilesbie.
The reason My Immortal just ends abruptly is because her bible-thumper parents found out about it after searching her web history. They take away Tara's computer and ground her for swearing on the net, writing about sex, self-harm, worshiping Satan (or Stan), and reading Harry Potter.

Poor Tara is left to her dreams, and is forced to re-enact every scene in My Immortal, along with things that make as much sense as her grammar and spelling, but with no dialogue, explanation or "sex" so it's not even funny anymore. She realizes how awful the THING she released onto the internet is, and is really very sorry. She contemplates deleting it off her FF account if she ever gets her computer back, but realizes that even if she deletes it, people will keep on finding copy-pasted versions and reading it.

She then sees that there is another way.

LSD Dream Emulator is either a continuation of Madotsuki's dreams, or what her dreams were like before she became a hikikomori.
LSD: Dream Emulator is a bunch of abstract, distorted representations of what it's like in the real world. Like Yume Nikki, it's completely open for what it all means.

Also, for the "Madotsuki is Kikiyama and the game is an adapted horror book by a Nightmare Fuel Station Attendant and/or seriously creepy little girl" theory, maybe Kikiyama landed a job at Asmik Ace when she grew up? The person who wrote the dream diary the game was based on WAS a woman. Or perhaps an older female relative got a hold of Kikiyama's/Madotsuki's older diary from before she had the "isolated til I'm done with the story" idea?

Madotsuki encountered The Slender Man when she was a child.
He may not have appeared in the dream word itself, but his effect on her is obvious. May or may not overlap with the rape theories. She may have become a Masky, memories of which Uboa represents.

Madotsuki is a Time Lord.
I'm surprised no one mentioned it already.

Madotsuki is a descendant or distant relative of Sakuya Izayoi.
Two Effects she can find (and arguably two of the more useful ones) are a Knife and the Stoplight. In other words, increased stabby potential and the ability to freeze everything in place. Also, both are shown in their own games as having bright red eyes (Cat Effect).

Madotsuki is a Magical Girl who ran away from her endless battles
Specifically, she's a Puella Magi (Danbooru link, may contain NSFW ads). But she learned the Awful Truth, and also had to watch her fellow Puella Magi die or turn into Witches. So she gave up and turned into a Hikikomori, thinking that she would at least enjoy some normal days before turning into a Witch. However, things weren't so simple. The memories of her time as a Puella Magi still tormented her in her dreams. For example, the different areas are Witches' lairs, the Toringen are familiars, Poniko was one of her friends, and Uboa is the Witch that she turned into. And so, after having all these fucked-up dreams for so long, she finally decided to commit suicide.

IT ALL MAKES TOO MUCH SENSE. Here, have some explanations with visuals:


 * Another version of Madotsuki's outfit; Madotsuki first meeting Kyube,Madotsuki and her fellow Magical Girls; Poniko going Witch, alternate rendition of Madotsuki facing Uboa - notice Poniko's empty body being held within it; the first time Madostuki got sucked into a Witch-Realm after witnessing a Witchkissed friend stab themselves; Madotsuki finally turning into a witch; and Madotsuki's witch form (Danbooru links, may contain NSFW ads).
 * The fate of her friends? Monoko died a horrible death being mutilated by a Witch (hence her odd misshapen appearance when you use the Stoplight on her), Monoe couldn't take it and faded away after smashing her Soul Gem before she could suffer Terminal Corruption, and Poniko became the Witch Uboa (Which particularly traumatised Madotsuki since it happened during a sleepover) - I like the implication that she was having a sleepover with Poniko to try and keep her friend's spirits up, but Poniko's trauma was too great and she became Uboa right in front of poor Madotsuki in spite of an attempt to mercy-kill her by stabbing.
 * While everyone assumes that Monoko's deformities are indicating that she died, in this case she may have become a Witch as well, and her growing multiple arms represents her transformation. Stoplight!Monoko may even be the witch Patricia, though that's a bit of a stretch. Also being killed and witching aren't mutually exclusive, unless the Soul Gem breaks. Monoko could have also been horrendously injured and then witched as a result of it; witching out by running out of magic while regenerating from horrific mutilation is a pretty grim fate.
 * Alternatively, Poniko's Witch form is the bleeding multi-armed monster in the background of the area Uboa takes you to. Uboa is its familiar. Witches tend to be more complex-looking then their familiars, after all.
 * In Madoka Magica, one of the Witches Fought was H.N. Elly, the Hikkikomori/Box Witch. One of her primary Motifs was Flying Wings and some Checkered patterns. Guess the Yume Nikki character who is a Hikkikomori and has checkered patterns and flying as motifs normally associated with her. And don't the bluish things in this picture of Elly's barrier look an awful lot like Mars-san?
 * There's lots of symbolism behind Madotsuki's powers in-dream, such as that decapitation one being the time she lost her own head but somehow survived because her Soul Gem was intact. The Crashing event in the Famicom World could have been an combination of the times her old RPG cartridges glitched and the time she got stuck inside a Witch's maze after getting separated from her friends, only escaping once they beat the Witch. The Toringen? They were beefed-up Familiars that managed to survive her knife attacks, and their attempts to kill/imprison her traumatized her badly.
 * Alternatively, all the the powers/eggs that Madotsuki collects within her dreams could represent all of the Soul Gems of fallen Magical Girls that Mado wishes to save. Soul Gems are egg-shaped by default, are they not?
 * Mars-San is a Witch and Masada is its familiar. The Spaceship and Mars areas are Mars' realm. Masada's duty as Mars' familiar is to take Magical Girls and other victims deeper into Mars's realm. Also there are multiple Masada-familiars that pilot the "spaceship"; this is apparent from Masada always appearing to respawn in front of the piano whenever you exit and reenter the room after killing him within the game. Furthermore, befitting the creepy Puella Magi series, the Masada familiars look neither Bishounen nor Moe as commonly depicted by the Yume Nikki fanart community; they actually look nightmarish like this. And concerning Mars-San, the Magical Girl who became Mars was really interested in astronomy and science fiction, explaining Mars' space travel-themed Witch realm. And once Madotsuki encountered and started attacking Mars, she gained the realization that Witches were more than simple Eldritch Abominations. Even as Madotsuki attacked it, Mars wouldn't fight back and continued to weep quietly to itself...
 * So when Madotsuki finally acquired all the powers, she realised her own Gem was fading and tried to off herself before she became a Witch. Unfortunately, given the Familiars that surround her broken body in the ending, she may have become a Grief Seed before landing. ~the User:Ace Of Scarabs

Madotsuki is a Reyvateil

 * And the whole game is exploring her Cosmosphere.

Madotsuki isn't dreaming, she's exploring her Reality Marble.

 * The intense, protracted isolation (and whatever trauma you think is appropriate) she's experienced has led her to develop an unusually bizarre Reality Marble, without her being aware of it. She probably thinks she's dreaming or crazy.

Madotsuki is unknowingly a fourth Powerpuff girl.
The dreams are nightmares sent by HIM to scare and confuse her. She locks herself in her apartment because she is frightened that she may hurt other people with her powers. By collecting all of the effects (which may be nods to her powers or aspects of her personality) and dropping them in the nexus (the center of her mind) she finally realizes who she is and jumps off the balcony, flying away offscreen to join Blossom, Bubbles, and Buttercup. The jellyfish creatures in the ending are trapped in a dark space by HIM as punishment for failing their mission.

The "Wilderness" area is the same place as the Salad Fingers universe's main setting.
Both settings consist mainly of grey sand and tangling weeds/plants, and have quiet, calm background music. While lost/wandering children may be found here, on occasion many interesting...creatures may be encountered in these desolate places as well. Additionally, both Yume Nikki and Salad Fingers are notorious on the internet for being Surreal Horror works that are massive sources of Wild Mass Guessing and Body Horror. Finally, both series' main protagonists Madotsuki and Salad Fingers may or may not be utterly insane.