Isekai by Moonlight/Characters

Characters from , as of the end of the third chapter, include:

Original Characters
In order of appearance:

"Robu-san" Donaldson / Oni
"Stupid genre conventions."

- Robu-san's Catch Phrase


 * First appearance: Chapter 1.
 * Licence status: Not available to other writers

The Protagonist of Isekai by Moonlight, the story is told from Robu-san's perspective. A full description of Robu-san would include major spoilers for the story. However, it isn't much of a spoiler for a story titled Isekai by Moonlight to reveal that he's Trapped in Another World.

At the beginning of the story, he's a 14-year-old white male in Japan, who stands 183 cm tall. Despite this, there are enough other tall white men in Minato (because of all the embassies in that part of Tokyo) that nobody has yet figured out his secret identity. (Well, except for a couple of opponents who ended up dead so it doesn't count... and Sailor Pluto already knew.) Robu-san's birthday is July 7, Tanabata.

Usagi inadvertently gave him his non de guerre "Oni"; it's the first word that she said to him.

Robu-san, Makoto, Ami, and Ryou learned the Lyrical Nanoha style of telepathy when they were "sent to another dimension". He also knows how to maintain and repair Intelligent Devices and Unison Devices, assuming he has access to the needed parts.

In the third chapter, he accepts Makoto's proposal of marriage, becoming her fiancé.


 * Affectionate Nickname: The "True Companions" version; Robu-san calls Tsukino Usagi "Bunny-chan" and Artemis "Artie".
 * First-Name Basis: With most of the Senshi, and with Ami's mother.
 * Genre Savvy: His early blind spot about his relationship with Makoto notwithstanding. Early in the first chapter, he worries that "Stupid genre conventions" is becoming his Catch Phrase.
 * Just Woke Up That Way: The Ontological Mystery subtype. Robu-san wakes up teen-aged, at the start of the story.
 * Nom-de-guerre: "Oni" was given to him accidentally by Usagi; it's the first thing that she called him (because of his height), he used it in an I Know You Know I Know situation, and it stuck.
 * Official Couple: With Kino Makoto, as in her writeup. The two are on a "first name without honorifics" basis by the end of the first chapter, and engaged by the end of the third chapter.
 * The One Guy: For part of the first chapter, when (as in canon) Tuxedo Kamen was kidnapped.
 * New Transfer Student: How Robu-san enters the story.
 * Sarcastic Clapping: One of Robu-san's favourite ways to draw attention to himself and away from the Sailor Senshi. The trope being unknown in Japan in the early 1990s, the clapping serves less as a psychological attack and more as a distraction.
 * Smart People Play Chess: Robu-san cheats here by using Ami's skills... but he still can't win against her, or against when she takes an interest in the game.
 * Super Empowering: In his backstory.
 * Trapped in Another World: He's the Protagonist in an Isekai story; this trope's pretty much a given.
 * True Companions: Thanks to being sent to another dimension for the third chapter of Isekai by Moonlight and returning together, Robu-san is almost as close to Ami, Ryou, Kasandara, Meia, Sakura, and Ichiro as he is to Makoto.
 * True Companions: Thanks to being sent to another dimension for the third chapter of Isekai by Moonlight and returning together, Robu-san is almost as close to Ami, Ryou, Kasandara, Meia, Sakura, and Ichiro as he is to Makoto.

Sato Kichirou

 * First appearance: Chapter 1.
 * Final appearance: Chapter 1.
 * Licence status: Available to other writers upon request.

A rather Flat Character, who existed to give Robu-san and Ami a classmate that they didn't want to spend time with or share their secrets with. He ended up.

Aoyama Ichigo
""I think I've figured it out," she said after being introduced to Hino-san. "You're the Sailor Senshi that I remember hearing about during the Missing Time.""

- Chapter R


 * First appearance: Chapter 1.
 * Licence status: Available to other writers upon request.

Ichigo Aoyama is just an Ordinary Junior-High School Student, who is a classmate to the decidedly not normal Makoto Kino. At the start of the story, she's 14 years old, she stands 166 cm tall, and her birthday is January 22. Ichigo wears her black hair at shoulder-length.

She was born and raised in Wakkanai, Hokkaido, the third of three children. Her father and both of her brothers are deep-sea fishermen. Ichigo and her mother moved to Tokyo so that she could get a better education than what was available in Wakkanai; Ichigo wants to become a marine biologist and study her home town's harbour seals. She loves the biological sciences, and absolutely hates Japanese History to the point that she needs to take supplementary lessons in that class.

One reason that she hates Japanese History class is because it teaches her some things that her family tell her aren't true. Ichigo knows more about the Ainu than most college students... because she is Ainu herself. This isn't something that she tells very many people; when pressed, she says she has Ainu ancestry without saying that it's on both sides of her family. Ichigo has the Ainu depressed nose root and projecting cheekbones.

She knows "a smattering" of Russian, which she admits to speaking with a thick Japanese accent, from the occasional trip to Korsakov. She loves downhill skiing.

She often speaks without thinking first, which leads to the occasional awkward moment.


 * Secret Keeper: For both the Sailor Senshi and Robu-san, partway through the second chapter.
 * The Team Normal/Ordinary High School Student: While she isn't a formal member of the team, she isn't a Magical Girl Warrior or a Designated Victim, either.

The Companions

 * First appearance: Chapter 3.
 * Licence status: Not available to other writers

These allies to the Official Couple and Beta Couple joined that group when they were sent to another dimension in the third chapter. The "other dimension" happened to be the one that is home to Midchilda from Lyrical Nanoha; these particular Midchildans are Unison Devices except for one Intelligent Device who is Ryou's ally.


 * Trapped in Another World: By choice; they volunteered to join the Official Couple and Beta Couple in their home reality, fully expecting that they'd never be able to return to their original reality.
 * True Companions: As a group, Kasandara, Meia, Sakura, and Ichiro are siblings in all but blood, and they treat Robu-san, Makoto, Ami, and Ryou the same way.

Kasandara
Ryou's Intelligent Device. She uses the hiragana spelling かさんだら instead of the Midchildan spelling Cassandra because Ryou named her before he was sufficiently fluent in English to pronounce her name "correctly".

Kasandara is able to boost Ryou's precognitive power so that he can see more potential futures than he can on his own. Kasandara has no precognitive power of her own; she must piggyback on Ryou's power.

She only has a basic personality to begin with; both Kasandara and Ryou preferred her to grow into her full personality, whatever that might be. Robu-san thinks that her voice sounds like Ayako Kawasumi's when she played Chikage in Sister Princess, although he hasn't mentioned that to anyone.

Sakura
Makoto's Unison Device. Playing against type, she's a down-and-dirty fighter and definitely not a proper lady. She uses a katana that is scaled to her size, and gives Makoto the ability to use and channel Senshi attacks through a blade when in Unison. Sakura is the tomboy to Meia's girly-girl. She considers Meia and Ichiro to be siblings, and is friends with the other Companions.

Meia has electric-blue hair, and so does Makoto when they're in Unison. After Robu-san pointed out the similarity in their voices and preferred weapon (but only their voices and preferred weapon), Makoto named her after the character played by Chisa Yokoyama in Sakura Wars.


 * Cherry Blossom Girl: Averted hard; the only thing she has in common with the trope is her name.
 * Combat Pragmatist: In the fourth chapter, she's shown to not be above fighting dirty, when she.
 * Honest Advisor: Sakura isn't afraid to call out Sailor Moon when Usagi chastised others for acting the same way she did earlier. After a few days of thought, Usagi asks Sakura to keep doing just that.
 * Tomboy and Girly Girl: As mentioned above, Sakura is the tomboy to Meia's girly-girl.
 * You Gotta Have Blue Hair: Electric-blue, to be precise.

Ichiro
Eldest of the companions by one day, Ichiro is Robu-san's Unison Device. He dual-wields katana that are scaled to his size, and shares his sword and magical skills with Robu-san when they're in Unison. (Robu-san can manifest forcefield swords when required.) More mundanely, he knows enough about etiquette and high society to be able to dance formally, and enough about the TSAB training curriculum to be able to teach most of it. He considers Sakura and Meia to be sisters, and is friends with the other Companions.

Ichiro has jet-black hair, and so does Robu-san when they're in Unison. Robu-san named him after the character played by Akio Suyama in Sakura Wars, to match Sakura.


 * Cultured Badass: as described above.

Meia
Ami's Unison Device, named after the Pleiad Maia because she somehow reminded Ami of her mother. She's nurturing like her namesake, and a proper Yamato Nadeshiko; she's the girly-girl to Sakura's tomboy... but she's still as competent a fighter as any other TSAB Unison Device. Meia prefers to assist Ami with healing and combat spells, using both Lyrical and Senshi magic, and can cast Lyrical healing spells on her own when needed.

Meia has sea-green hair, and so does Ami when they're in Unison. Like the mythological Maia, this Meia has black eyes. Her voice sounds remarkably similar to Luna's.

She considers Sakura and Ichiro to be siblings, and is friends with the other Companions.


 * Lady of Black Magic / White Magician Girl: Her personality and powers combine both tropes; she's a healer and a fighter, much like Ami.
 * Tomboy and Girly Girl: As mentioned above, Meia is the girly-girl to Sakura's tomboy.

Shario-chan
After the events of Magical Girl Lyrical Nanoha StrikerS, one would think that the TSAB would stop looking for shortcuts to combat power. One would be wrong. They got Robu-san to put a personality that he'd copied via brainprint into a Device in an effort to create a more powerful Unison Device... but he gave them the one personality he had copied who had no magic at all: Shario Finieno. This got the TSAB off his back. Then he made another "Shario-chan", with the original's permission, to help with maintaining the other companions' bodies. Except for the height difference, she's almost identical to Shario as of the end of StrikerS.

Once she's met the rest of the Sailor Senshi and their Secret Keepers, Shario-chan ends up working with Naru Osaka during the fourth chapter.

Because she is not a mage, she cannot Unison.


 * Cloning Blues: The "robot doubles" subtype, played with. She has all of Shario Finieno's memories up to when she was imprinted with them, and looks and sounds like Shario. Also played straight in that the Shario-chan shown in the fourth and later chapters is the second Device with Shario's memories.
 * I'm a Doctor, Not a Placeholder: "I'm a device meister, not a carpenter."
 * Wrench Wench: The rare subtype that handles pure electronic devices – namely, the other Midchildan Devices, the mundane computers that her human friends brought back from the Lyrical reality's Earth, Artemis' computers and other systems from the Silver Millennium, and the Mercury Computer.

Hayate-chan
The youngest of the companions physically, but the oldest mentally because she has Hayate Yagami's memories as of the end of Magical Girl Lyrical Nanoha StrikerS. However, she's "only" a Rank B mage. Like Shario-chan, she exists because of the experiments that Robu-san carried out for the TSAB. Instead of being in charge of the Lyrical reality's Devices, she's their Cool Big Sis... but she's still the best strategist of the story's characters.

While she looks for a purpose in life, she teaches tactics and leadership skills to Ryou, Robu-san, and the Senshi... including Chibiusa.


 * Cloning Blues: The "robot doubles" subtype, played with. She has all of Hayate Yagami's memories up to when she was imprinted with them, and looks and sounds like a miniature version of Hayate.
 * Quickly-Demoted Leader: Voluntarily. Sailor Moon is her new team's leader, and Hayate-chan accepts that.
 * Watsonian Versus Doylist: Why she's only a Rank B mage. The Watsonian reason is that there's only so much magical capacity in a chassis the size of a Unison Device; Word of God is that the Doylist reason is so she doesn't overshadow the Sailor Senshi.

Sakamoto Kazuya

 * First appearance: Chapter 4.
 * Licence status: Available to other writers upon request.

A classmate of Robu-san and Ami. He's interested in Minako, but Robu-san doubts she'd be interested in him.

OC Stand-Ins
The section headers link to the canon character descriptions. Again, in order of appearance:

Urawa Ryou / Onmyōji
""This should be interesting." When a precog says something like that, it's best to play along."

- Chapter R


 * First appearance: Chapter 1.

No longer a two-episode guest character, Ryou transfers to Kuritsu Juban Chuugakkou during the second chapter in order to get a better education than he could get back at home – which for the purposes of Isekai by Moonlight is the port city of Niigata (based solely on the fact that we saw him board a shinkansen to return home at the end of his first appearance). He still has his precognitive power, although he can't see a definite future; instead, he sees a number of possible futures and has to figure out which one is most probable or most desired... and if those two futures aren't the same, he has to take steps to make the future he wants come about.

One future that Ryou-san didn't need to work to make happen is the one where he and Ami fell in love. By the end of the second chapter of Isekai by Moonlight, Ami and Ryou are the story's Beta Couple.

Unlike the others who were sent to another dimension for the third chapter of Isekai by Moonlight, Ryou doesn't have the physical constitution to be able to handle a Lyrical Nanoha style Unison Device. Instead, he has an Intelligent Device as an ally; see Kasandara's entry in the original characters section for more about this.

Ryou, Ami, Makoto, and Robu-san learned the Lyrical Nanoha style of telepathy when they were sent to another dimension.

In the fourth chapter, he gets his nom-de-guerre when Sailor Pluto calls him Onmyōji. He also receives his parents' permission to marry Ami once he's of age; Mizuno-sensei insists that he take Ami's family name, making him a mukoyōshi.

For the purposes of this story, Ryou's birthday (never established in canon) is December 23, which makes him a few months younger than his girlfriend.


 * Ascended Extra
 * Beta Couple: With Ami, as described above.
 * Chick Magnet: Downplayed, but he still draws more female interest than anyone else in the story. Ami in the first chapter (as per canon and the only one whose interest he reciprocates), and in the third chapter all show interest in him.
 * Seers: As mentioned above.
 * Spell My Name with an "S": "Ryou" instead of the canon "Ryo", as a subtle reminder that this story takes place in a close parallel of the canon anime timeline instead of in the canon anime timeline itself.
 * True Companions: Thanks to being sent to another dimension for the third chapter of Isekai by Moonlight and returning together, Ryou is as close to Makoto, Robu-san, Kasandara, Meia, Sakura, and Ichiro as he is to his own family.

Mizuno Saeko
""Would you be happier if I forgot what's been said here today?""

- Chapter R


 * First appearance: Chapter 1.

Isekai by Moonlight is using Mizuno-sensei's given name from Pretty Guardian Sailor Moon. No longer a one-scene guest character with no lines, she spends a lot of time on-call at the hospital in order to pay for her daughter's juku, but unlike in canon she isn't completely absent from Ami's life.

Early in the second chapter, she decides to become an unofficial parent figure to both Makoto and Robu-san, neither of whom have living parents in the story. Later in the second chapter, she was in the audience for the Snow White play that was staged in episode 56 of canon, and demanded an explanation as to why her daughter claimed to be a transforming heroine when Ami arrived home that evening. As a result, she's aware that Ami, Makoto, and Robu-san are Sailor Mercury, Sailor Jupiter, and Oni, respectively. A later slip of the tongue lets her in on Sailor Moon's identity as well, which she offers to keep secret from the Tsukino family.


 * Ascended Extra
 * Glamorous Single Mother: Downplayed, in that she is sometimes working overtime instead of at home, but that's because she needs the extra money for her daughter's education.
 * Good Parents/Open-Minded Parent: Once she learns that her daughter is Sailor Mercury, her main interest is in what it's like to be a transforming heroine.
 * I Want Grandkids: Turned Up to Eleven in that she wants to ensure the continuation of the Mizuno line. In the fourth chapter, she offers Ryou the status of mukoyōshi in the Mizuno family on his 20th birthday (not taking into account his two years in another dimension) to ensure Ami has a husband who takes her family name. Saeko adopts Minako later in the same chapter, after Minako had been disowned by her mother for being a Senshi.
 * Parental Substitute: For Makoto and Robu-san, once she learns that they have no living parents and are close friends with her daughter. She's just as much an Open-Minded Parental Substitute as she is an Open-Minded Parent.
 * Secret Keeper: For Usagi, Ami, Makoto, and Robu-san, by the end of the second chapter.

Mochizuki Ka'o

 * First appearance: Chapter 4.

This character never appeared in canon with the name "Mochizuki Ka'o". Her name in Isekai by Moonlight is written this way:
 * Mochizuki: 望月 – full moon (literally 望 (mochi) "wish, desire", 月 (tsuki) "moon")
 * Ka'o: 伽桜 – 伽 (ka) "attendant, nurse", 桜 (o) "cherry blossom"

Her new name connects her to her Black Moon existence as the droid Pharmakon. Ka'o had her obedience routines deleted by Meia during what in canon was "Venus Minako's Nurse Mayhem" (just after Ka'o pinned Venus to the wall), and she immediately switched sides; she was programmed to act like a nurse and help people, but Esmeraude forced her to hurt people.

After defecting to the good guys, Ka'o learned all of the non-magical medical knowledge that Ami brought back from Hayate's reality. She can still transform to a medical-themed combat form, but prefers not to. She's planning to work for either Ami or Mamoru once one of them graduates from medical school. Until then, she lives with the Mizuno family.


 * Heel Face Turn: As described above.

Changes (if any) to Canon Characters
Starting with the two who have major roles in Isekai by Moonlight, then listing the others alphabetically by family name.

The section headers link to the canon character descriptions.

Kino Makoto / Sailor Jupiter
Makoto is the deuteragonist of Isekai by Moonlight and Robu-san's girlfriend. He trusts her with all of his secrets, including the ones that hurt, and in return she trusts him with all of her secrets, including the ones that hurt. And that trust has turned into love. She knows that Robu-san will never willingly lie to her, although he's reserved the right to remain silent or to give a misleading answer. By the end of the first chapter of Isekai by Moonlight, Makoto and Robu-san have kissed, and are the story's Official Couple.

She and Robu-san developed a "Jupiter Railgun" attack during the first chapter of Isekai by Moonlight, and she unlocked the canon manga attack "Jupiter Coconut Cyclone" during the story's second chapter.

Extrapolating from canon, the plane crash that killed Makoto's parents has been established in-story as the JAL123 crash, which in the late 1980s and early 1990s in Japan was what was understood to be the case when anyone mentioned a plane crash without saying which one. Considering her canon nervousness when she hears aircraft, and her near-compulsion to keep things clean, this story's Makoto has been established in-story as having been aboard the 747 with her parents, and is one of a small number of people who survived the crash in that reality who died in real life. And she hates the minor notability that this brings, which is why people rarely talk about it.

She's a bit jealous of anyone else who Robu-san might notice as a romantic interest. But only a bit. She's willing to transform to and from Sailor Jupiter in his presence (but not any other man's presence), giving him the occasional "eyefull". She wasn't happy that they waited until she was 16 before taking their relationship to the next level, but understood why that has to be.

By the end of her intensive training during the "sent to another dimension" story arc, Makoto has unlocked all of her canon attacks from the original anime, the manga, Pretty Guardian Sailor Moon, and Crystal, and can use any of them without standing, posing, and calling the attack (although at reduced power and accuracy). She's also developed an "electro-quarterstaff" that she can use as a polearm. Makoto, Ami, Ryou, and Robu-san learned the Lyrical Nanoha style of telepathy when they were "sent to another dimension". Makoto is also strong enough when transformed to Sailor Jupiter to be able to use a Unison Device without taking damage; see Sakura's entry in the original characters section for more about this. Makoto can fly while in Unison with Sakura. Since some of Sakura's powers depend on Makoto using a sword, she's also been given many months of TSAB swordswoman training and owns a nonmagical ō-wakizashi that she's named Donguri-no-ken (literally "acorn sword").

In the third chapter, she proposes marriage to Robu-san, becoming his fiancée.

"Considering how messy an aircraft crash usually is, I could understand why she was a neat freak."
 * Character Focus: She appears in more, and longer, scenes than any of the other Senshi.
 * Darker and Edgier: In the fourth chapter, she ... which upset her greatly.
 * First Girl Wins: In the first chapter, no less.
 * Neat Freak: As in canon, but given a reason here that ties in with her parents' death.


 * Official Couple: With Robu-san, as described above.
 * Raised by Grandparents: Mentioned in the second chapter, but the fact that Makoto lives alone shows that their parenting style is extremely hands-off.
 * Took a Level in Badass: When she was sent to another dimension in the third chapter, as described above.
 * True Companions:
 * Thanks to Mizuno-sensei becoming Makoto's Parental Substitute in the second chapter, the canon friendship between Makoto and Ami has only grown closer. At one point, Makoto says that they're "sisters in all but blood".
 * Thanks to being sent to another dimension for the third chapter of Isekai by Moonlight and returning together, Makoto is as close to Ryou, Kasandara, Meia, Sakura, and Ichiro as she is to Ami.

Mizuno Ami / Sailor Mercury
Ami-san is still the genius of the team. She has a boyfriend in this story; see the write-up for Urawa Ryou for details.

Like Makoto, Ami knows that Robu-san will never willingly lie to her, although he's reserved the right to remain silent or to give a misleading answer.

Her canon very-mild Innocent Fanservice Girl tendencies have been played up slightly; she honestly doesn't care whether Ryou or Robu-san do or don't see her naked, which saves a bit of time when she needs to transform to or from Sailor Mercury in their presence. This is explained in-universe by her having the same attitude toward skin that most doctors and medical students develop.

By the end of her intensive training during the third chapter, Ami has unlocked all of her canon attacks from the original anime, the manga, Pretty Guardian Sailor Moon, and Crystal, and can use any of them without standing, posing, and calling the attack (although at reduced power and accuracy). She can also fly unaided, and she has developed an "Frigid Sword" that she can use in close-range combat, Ami, Ryou, Makoto, and Robu-san learned the Lyrical Nanoha style of telepathy when they were sent to another dimension. Ami is also strong enough when transformed to Sailor Mercury to be able to use a Unison Device without taking damage; see Meia's entry in the original characters section for more about this.


 * Awesomeness By Analysis: The only time that she was in Unison with Reinforce Zwei, Ami learned not only all of the spells that Rein cast – she cast each spell only once – but also how to fly unaided. This means that Ami figured out the basics of Midchildan magic, during combat, in less that five minutes.
 * Beta Couple: With Urawa Ryou, as described in his writeup.
 * Character Focus: She appears in more, and longer, scenes than any of the other Senshi except Makoto.
 * Darker and Edgier: In the fourth chapter, she.
 * Smart People Play Chess: Shown once in canon, but is shown repeatedly in this story beginning in the third chapter.
 * Took a Level in Badass: When she was sent to another dimension in the third chapter, as described above.
 * True Companions:
 * Thanks to Mizuno-sensei becoming Makoto's Parental Substitute in the second chapter, the canon friendship between Makoto and Ami has only grown closer. At one point, Makoto says that they're "sisters in all but blood".
 * Thanks to being sent to another dimension for the third chapter of Isekai by Moonlight and returning together, Ami is as close to Robu-san, Kasandara, Meia, Sakura, and Ichiro as she is to Makoto.

Aino Minako / Sailor Venus
In Isekai by Moonlight, Minako transferred to Kuritsu Juban Chuugakkou instead of the canon Shiba Kōen, and she asked to have a Conversational English club created when she transferred in. Since the club's founding members are Minako, Ami, and Robu-san, this has turned into an unofficial planning forum for the Sailor Senshi who are fluent in English... at least when club advisor Sakurada-sensei doesn't sit in on club meetings.

In the fourth chapter, Minako was the first of the Senshi who hadn't been sent to another dimension to learn Lyrical Nanoha style telepathy and Ami's instant-transformation technique. This was after she was disowned by her mother for being a Senshi and before she moved in with Makoto. When Ami's mother discovered she had been disowned, she quickly arranged with Minako's father to adopt Minako.

As of the end of the fourth chapter, Minako is usually still the serious mature girl from the first season of Sailor Moon, not the malapropism-spouting goofball that she becomes starting in episode 78 of canon; being disowned by her mother put a damper on her sense of humour. She's also developed a non-canon close-in energy attack, "Crescent Beam Saber".


 * Darker and Edgier:
 * The events of the Sailor V manga are included in the backstory of Isekai by Moonlight... which means that, unlike in the canon anime, Minako has blood on her hands.
 * In the fourth chapter, she She immediately called the police.
 * Have You Tried Not Being a Senshi?: A less-understanding variant. At the start of the fourth chapter, Minako tells her parents that she's Sailor Venus. Her mother's response was "The newspapers all say that people who get involved with the Sailor Senshi get hurt, or worse. And you want to be one? No." When Minako replied she's been a Senshi longer than the others, her mother immediately kicked her out. Minako moved in with Makoto.
 * Happily Adopted: Later in the same chapter, she joins the Mizuno family with her father's permission.

Artemis
Robu-san is one of the few people who can get away with calling Artemis "Artie". He's been shown to take a role in running the Crown arcade, and is responsible (after Robu-san suggested it) for the Sailor Moon toku shows that exist in Minato (including the one seen in canon). He does remember what it means to be a Mau, although he never transforms between cat and human forms where Luna can see him. He spends most of his time in cat form.

Artie is the only person who Robu-san trusts with access to his collected data, until Robu-san gives the Midchildan Companions access during the fourth chapter.

In the fourth chapter, Artemis learned Lyrical Nanoha style telepathy from Ami.

Chiba Mamoru / Tuxedo Kamen
No changes yet, other than Mamoru knowing Robu-san and him knowing he's Tuxedo Kamen. Unlike the others, they are not on a given-name basis as of the end of the second chapter of Isekai by Moonlight, and the fourth chapter shows that they don't get along well. Mamoru's still Usagi's boyfriend and protector, and he's probably still going to become King Endymion eventually.

Hino Rei / Sailor Mars
No substantial changes yet, other than Rei knowing Robu-san and him knowing she's Sailor Mars. She's still a shrine maiden without a boyfriend, no matter how much Yuuichirou-san would prefer otherwise.

In the fourth chapter, Rei learned Lyrical Nanoha style telepathy from Ami.


 * Darker and Edgier: In the fourth chapter, she

Luna
No substantial changes yet, other than Luna knowing Robu-san and him knowing – and telling her – that she's a Mau. He didn't tell her what that meant, though.

In the fourth chapter, Luna learned Lyrical Nanoha style telepathy from Ami.

Meioh Setsuna / Sailor Pluto
Because of the right royal mess that Robu-san is making to the timeline simply by being in it, Sailor Pluto has four versions of herself involved in the story. The version in Crystal Tokyo is coordinating the actions of the other three: the Silver Millennium Pluto guarding the Door of Space-Time, the Setsuna Meioh native to the current time who is enrolled in medical school, and a Setsuna from between the current time and Crystal Tokyo, who owns and operates Atelier Lucent, a trendy clothing store on Center Gai in Shibuya (thus explaining at least some of the contradictions in her canon backstory).

Atelier Lucent's Setsuna has spoken with Robu-san, months before the contemporary Sailor Pluto canonically makes contact with the other Sailor Senshi. She's also made a few outfits for Makoto, not that Mako-chan realizes who her favourite fashion designer is. (Although Atelier Lucent isn't on the approved list of sources for the Kuritsu Juban Chuugakkou school uniform, so Setsuna can't help Makoto there.)

Makoto finally recognizes Setsuna as Sailor Pluto during the fourth chapter. Later in the same chapter, Setsuna learned Lyrical Nanoha style telepathy from Ami, and helped Ryou sell the gold he brought back during the third chapter.

Osaka Naru / Okuni
""If it was supposed to be a secret, you shouldn't have dropped so many hints.""

- Chapter 1

Unlike in the canon episode 32, Zoicite didn't miss when he tried to turn Naru into a youma. This pissed off Sailor Moon to the point where she let slip a couple of things that she shouldn't have, and once Naru was refreshed, she confronted Usagi, Makoto, and Robu-san about their secret identities. The Senshi quickly brought Naru into their confidence. When Luna restored the Sailor Senshi's memories at what in canon was the beginning of Sailor Moon R, she restored Naru's memories at the same time.

Her brief time as a youma left Naru with a metahuman power to create gemstones (but only diamonds in the first chapter of Isekai by Moonlight), and a transformation complete with kabuki makeup in the mukimi kuma style when she thinks that she's in peril. As of the end of the second chapter, the meaning of this makeup is unknown.

Starting in the fourth chapter of Isekai by Moonlight, Shario-chan teaches Naru how to use her gem-creation power to make replacement parts for the Midchildan Devices.. In parallel, Ichiro and Sakura teach Naru how to actually use the crystal swords and knives that she creates. This is also the chapter where she gets her nom-de-guerre, when Sailor Pluto calls her Okuni.

Naru does not keep any of this secret from her mother.


 * Cool Mask: The "kabuki-style makeup" variant, at times of great stress.
 * Secret Keeper: For the Sailor Senshi and Robu-san, by the end of the first chapter.
 * Super Empowering: The ability to create gemstones might not be a combat power, but it's still a power.
 * Took a Level in Badass: The ability to create gemstone-bladed swords on the fly, though, is a combat power that she develops in the second chapter.

Usagi Small Lady Serenity / Princess Lady Serenity / Sailor Chibimoon
When Chibiusa met Robu-san, she discovered that he knew her real name.

In Chapter R, Return, Small Lady demonstrates that she's capable of a "Lyrical Nanoha" style Unison... by Unisoning with Hayate-chan during a literal a "do or die" situation. At the end of that chapter, she starts using the name "Princess Lady Serenity", although she still answers to Chibiusa.

Tsukino Usagi / Sailor Moon
""I'm stuck with that nickname, aren't I?""

- Chapter 1, just after Robu-san inadvertently calls her "Bunny-chan" and the others run with it.

No substantial changes yet, other than Usagi knowing Robu-san and him knowing she's Sailor Moon. She's still probably going to become Neo-Queen Serenity eventually.

In the fourth chapter, Usagi learned Lyrical Nanoha style telepathy from Ami. She also discovered that she can't Unison – not because she isn't powerful enough, but because she's too powerful to avoid overwhelming the Unison Device.

Like Makoto and Ami, Robu-san will not willingly lie to her (although he's reserved the right to remain silent or to give a misleading answer). Unlike Makoto and Ami, she does not know this.


 * Affectionate Nickname: The "True Companions" version; She gave Robu-san his nom de guerre of "Oni". In exchange, he calls her "Bunny-chan"... unless he's being completely serious.

Umino Gurio
After he ran for safety when she was turned into a youma, Umino and Naru are no longer a couple. Then An drained his energy past the point where he could recover quickly during preparations for the Snow White play, and he won't recover for months. In essence, he's been Put on a Bus earlier than in canon. Since his role as Mr. Exposition is filled by Robu-san and Ryou, Chuck Cunningham Syndrome appears likely for Umino.

The other Sailor Senshi
Isekai by Moonlight has not progressed to the events of Sailor Moon S yet, let alone Sailor Stars, so the other Senshi have not yet appeared. Robu-san did mention to Makoto and Ami in the first chapter that Sailor Neptune is the elegant one, though.