Interspecies Romance/Anime and Manga

"Remember, it only takes a little to get pregnant!"
 * Pokémon has a LOT of examples. Actually any romance involving a Pokémon is, except when it's between a gender counterpart race such as Nidorina/Nidorino and Volbeat/Illumise. Several Pokémon, Such as Meowth himself, Ash's Chikorita and Aipom and Harley's Cacturne have shown interest towards a human, but a human having interest for a Pokémon has yet to come.
 * Most famous is between Ash and Latias, a Legendary Pokemon to boot, from Pokémon Heroes.
 * But then there's anime version Gardenia...
 * Magical Pokémon Journey is full of this.
 * In Ah My Goddess, Belldandy is a Goddess and Keiichi is human. Although they both apear human, technically they are of a different species.
 * The manga mentions that Belldandy is actually a neutrino projection or something.
 * And then we discover that Belldandy's appearance (along with all the demons/gods in the series) is not her real appearance, it's just what we see. If a human sees a god/demon true appearence, that human's mind can shatter.
 * In Blue Submarine No. 6, Hayami has a semi-star-crossed romance with the mergirl Mutio.
 * The manga Nekoyome (literally "Cat-Wife") is about the married life of a human male and a female nekomata (who is a cat-sized bipedal anthromorphic talking cat!)
 * Played with in Inukami: During a Love Potion incident, Keita thinks about getting some interspecies loving with Youko and/or five of the other girls, until he realizes his kids would be half-dog, and is promptly disturbed about the whole thing. Kinda odd though since he knew at the time that Youko is a kitsune/fox.
 * Transformers: Kiss Players: A Japanese series where Moe Moe lolis had to make out with Transformers to give them superpowers. Most of them are in love too.How the fandom wishes we were making this up.
 * Nozomi (human) and Kouji/Coco (funny plush-looking tanuki-thing from another dimension), as well as Komachi (human) and Natsu/Nuts (funny plush-looking squirrel-thing from the same other dimension) in (you guessed it) Yes! Precure 5. To make things even worse, Nozomi is a middle schooler and Coco's human form is a middle school teacher.
 * Yes Pretty Cure 5 loves this trope. There's also all the subtext between Karen (human) and Milk (funny plush-looking rabbit-thing from that same other dimension). They are both female. Which leaves Rin as the only Cure not paired up with one of the mascots... and one episode centered around her and a ghost (not exactly different species, but close enough).
 * And in Mahou Sensei Negima, the girls of the Unwanted Harem who have an actual interest in Negi include a vampire, her Robot Girl servant, a ghost, and perhaps a half-Tengu. Perhaps in the half-Tengu's case because she seems more interested in her (human) classmate/childhood friend. Also, Natsumi seemed to really like Kotaro's half-wolf form.
 * And then there's the recently revealed Magical Land, which seems to be mostly populated with Humans, Petting Zoo People, some Funny Animals, even the odd demon. All of this little world is implied to happily mingle and reproduce without much regard for species.
 * The Hentai The Elven Bride is about a human/elf couple (as implicated by the title), and deals with the Fantastic Racism aspects of this. Well, it mentions them.
 * Hentai in general has a lot of this, usually women and monsters, though to be honest that's rarely romance.
 * To be fair, romantic examples can appear, as in Pretty Lamia.
 * Japan, particularly the h-doujinshi industry, has actually perfected entire genres of human-male/monster-girl pure-love romance (any possible species you can think of).
 * Don't forget the And Knowing Is Half the Battle of its sequel:

"Hikari: "If you're good, we can play 'Hide the Ferret' later!""
 * Kir from King of Bandit Jing hits on everything with two X chromosomes to rub together, and though he always gets rebuffed, it seems to have more to do with his personality than the fact that he is a bird.
 * An example that's not as jarring because of the What Measure Is a Non Human moments: Yu Yu Hakusho and its human/demon romances, namely (human and demon/yaminade),  and a female doctor (demon and human), and also  in the manga. Hell, you could count, as well, because of his demonic atavism.
 * Sailor Moon SuperS had ChibiUsa fall in love with an alicorn winged unicorn named Pegasus. Partially subverted in that he was really after her mind, not body, as the theme of that story arc was basically pure dreams, which ChibiUsa would have as a child. Though many people were disturbed not by the implied bestiality issues (his true form was human after all) as much as the fact that ChibiUsa was physically only about 8-10 years old at the time, while Pegasus'/Helios' age is never disclosed in the anime (some dubs actually gave him a voice of a grown-up man). This is somewhat less of an issue in the manga: Word of God stated that Helios is supposed to look like a seventh-grader (around 13-14 years old), and ChibiUsa herself eventually achieves a more grown-up form of Princess Lady Serenity (if temporarily). Additionally, in the manga she is Really About Nine Hundred And Two Years Old by the time she meets Pegasus.
 * There's also whatever the heck Peruru is in the SuperS movie and Chibiusa again. At the end she kisses him too. Pegasus has some competition.
 * Sailor Moon also had one of these in the side story The Lover of Princess Kaguya (basis for Sailor Moon S Non Serial Movie), where Luna falls in love with a human astronaut Kakeru. This one is also partially subverted: not only Luna's crush on Kakeru is one-sided (he is in love with his co-worker Himeko), but Luna later temporarily achieves human form, and in the manga she is later said to be an alien, so this form might have been natural for her.
 * There's also an implication of Artemis having a crush on Minako. At one point in the manga he is actually peeping on her while she's in the bathroom (which ends badly for him after Diana innocently reports the incident to Luna). In the anime, Artemis gives Minako a bouquet of roses in one episode to cheer her up. Again, in the manga he is an alien with a human form, but this isn't revealed until later on -- in fact, the cats being aliens from Mau was pretty much a Doing in The Wizard moment as they were never hinted to be anything more than magical cats (in the Sailor V manga Artemis is mostly treated as a housecat who just happens to be able to talk).
 * One chapter of Sailor V also had Artemis crushing on a small dog who happened to be named Luna-chan. While he probably mistook her for that Luna at first (the dog actually looks a lot like a cat, only giving herself away by barking), he still considers "marrying" her after the reveal until
 * In the Super S anime Artemis is implied again to feel like this... and mixing it with Hot for Preacher: his "target" is a beautiful Catholic nun named Sister Maria. Luna herself teases him a LOT for it, and thinks it's kinda cute.
 * Hippo and Yuuri in Mermaid Melody Pichi Pichi Pitch covers all the bases. Hippocampus that turns into a penguin that turns into a human falls in love with a tropical fish that also turns into a human. Whew!
 * Lawrence and Holo in Spice and Wolf: a human and a Trickster giant wolf who takes the form of a young girl (+ tails/ears) for almost all of the time. In volume 3 of the light novels/the first arc of the second season, after suffering a great psychological blow, she . Lawrence gets to thinking about this as well, and asks Deanna whether there is any record of human-deity couples. Apparently, there have been many.
 * Both examples are more in the Ship Tease category than actual romances, but the two biggest cases in the Slayers series are Princess Amelia and Zelgadis (a regular human and a chimera) and Xellos and Filia (a demonic priest and a golden dragon). Zelgadis and Amelia's case is subverted in that the former was once a human himself.
 * In the fifth season of the anime, there is the mechanical doll Ozel having feelings for the human priest Rezo, which in this case is unrequited.
 * And in the fifth Light Novel, the silver tiger beast/cult member Duclis spoke to the human protagonist Lina during his death that he had grown fond of her.
 * Rosario to Vampire has one semi-official coupling between (former) human Tsukune Aono and vampire Moka Akashiya. Meanwhile, several other Cute Monster Girls have their sights set on Tsukune.
 * Actually, just about any romance that takes place at Youkai Academy qualifies, and several Hybrid Monsters are seen in the first season.
 * Arguably, this is the entire premise of Kanokon (beside extreme Fan Service, with pinches of Shotacon.)
 * The eponymous character of Inuyasha is the product of a youkai (demon) and a human. He later goes on to have a romantic relationship with two human girls. Given the number of half-demons he runs into during the series (and a very enamoured wolf-demon), it seems that humans are a common youkai fetish, and vice-versa.
 * In one episode of the anime, a human woman named Princess Sara falls in love with Sesshomaru, Inuyasha's youkai half-brother.
 * In another, a Magical Girl Warrior was in love with a Youkai and they became a Battle Couple.
 * Shippo, a kitsune (fox-demon), falls in love with a human girl in one episode.
 * In another one a lizard demon falls for him.
 * It ain't a canon example by any means, but would that all interspecies romances looked like this (One's a cyborg, one's a vampire. Different species!).
 * It's mostly Human Aliens, and then there's the question of how you count Tenchi (he's part alien himself), but it's a central theme of the Unwanted Harem the poor kid has. Even the battleships have the hots for him. Well, two of the most powerful battleships in the galaxy, anyway. One manga shows a Terran girl making her case by being the only HUMAN interested in Tenchi.
 * Taken pretty seriously with the noted titles of Kanon and Clannad by Key Visual Arts. Both scenarios are demonstrated in a rather Tear Jerker route following the Beautiful All Along path, except...just replace beautiful with animal. The original visual novels take this detail a step further.
 * Happens all over Hyper Police: Natsuki is the product of this, Sakura (kitsune) has children with the timelost (human) samurai. Batanen (werewolf) has a huge crush on Natsuki (Half-human Catgirl), and Tommy (werewolf) has 19 (!) children with Poe (Human) in the manga.
 * Gash Bell features Wonrei and Lien, the only human-mamodo team in the series whose relationship very explicitly goes beyond friendship. Fortunately, since Wonrei is one of the few mamodo who actually looks like an adult human (and one of the most human-looking mamodo of the entire series), the trope's usual creepiness is wisely averted.
 * One of the things the three series that made up Robotech had in common, aside from the Transforming Mecha, was a Green Haired Space Babe who falls in love with one of the human pilots.
 * Actually this is a recurring theme in subsequent entries of the original Macross saga.
 * The Official Couple in Wolfs Rain is Kiba (a wolf) and Cheza (an Artificial Human made from flowers), much to his pack's envy.
 * In Inumimi, Yuichiro doesn't seem to be too interested in his dogs-turned-human (he pretty strongly averts All Men Are Perverts), but Elga at least seems to have a (non-sexual) interest in him. (And Emina is not happy about it.)
 * Now that she is human, Yuichiro feels uncomfortable with the same kind of physical contact compared to when she was a dog, leaving Elga feeling heartbroken and unloved. Rino blasts him for not being willing to return Elga's (platonic but unconditional) love for him, after which Yuichiro realizes she is "still Elga" and gives her the pats, hugs and cuddles she's been missing. Once she understands the whole story, Emina is almost entirely accepting of the situation. The whole thing avoids, inverts or averts a whole bunch of expected tropes, including this one.
 * Well, arguably at least only until he really hits puberty, before the Unresolved Sexual Tension gets resolved, considering that the creator also did an entire hentai tankobon called Inumimi Zukan: Encyclopedia of Dog-Style, which has become a modern classic among fans for being one of the definitive (full-color!) works on doggirls (here though, the dog-girls are actually shape-shifting dog-demons set in a modern Japan which is Spice and Wolf meets Shuffle).
 * In One Stormy Night, Mei the goat and Gabu the wolf are "friends", with a relationship dynamic much more like male lovers, Gabu's carnal predatory instincts only add to this, seeming more like intense homoerotic attraction.
 * Oruchuban Ebichu has Ebichu and Makun/Maa-kun
 * Hayate and Vita of Magical Girl Lyrical Nanoha. A human and her beloved Ridiculously Human Guardian Knight Program.
 * And for a more official example, we have Genya and Quint Nakajima, an Earthling and Mid-childan.
 * This happens a lot in Blue Drop, what with all the couplings between human women and Arume. Somehow it results in Half Human Hybrids, despite both parents being female and both parents being of different species.
 * Eureka Seven:
 * Wrong, dude. They were created to test whether it is worthy for Coralians to coexist with humans. Falling in love is an added bonus.
 * Eureka Seven takes this interspecies love approach seriously as  especially since their race are at war with each other.
 * Kyo Kara Maoh has Demon/Human relations. Although, for most of the series it is heavily frowned upon, to the point where Half-Demon Half-Human families have to live in their own villages.
 * Half demon half human offspring may or may not have magical abilities, as see by Conrart and Yozak (who have none), and El (who is ungodly powerful as a baby).
 * There is also something involving a guy (presumably a demon) and a panda which, even by the standards of this series is just utterly insane.
 * Bizenghast looks headed this way with Dinah (human) and Edrear (humanoid...bug...construct...thing). Edaniel also claims to have dated a human agent.
 * Yu-Gi-Oh GX has Juudai x Yubel. Juudai swore his love to her after she was transformed from a human into a humanoid dragon, and that didn't change even after death and rebirth. He just forgot about it for a while. He got better. And so did she. There's also Taniya x Misawa, even though Taniya is fairly human looking. She can just turn into a tiger and has very pointed ears.
 * GX is the series with most human x duel spirit ship tease, other examples are Sho x Dark Magician Girl (which is canon, even if they're not specifically together. Interest was shown on both sides.) and Fujiwara x Honest.
 * Given that Ahiru from Princess Tutu is a duck given human form, any relationship with her invariably involves some element of this,
 * Three Dragonball examples: Goku/Chichi and Vegeta/Bulma (both Saiyan/human) and Krillin/Android 18 (human/cyborg, though it may not really count since 18 was a regular human before being cyborgized). Later on, Gohan/Videl (half-Saiyan/human).
 * Given that none of the surviving Saiyans were female, it wasn't as if they had another option for reproduction.
 * The World God Only Knows has the possible pairings between Keima and Elsie, Haqua, and Diana.
 * One Piece has human and mermaid couples, and even a fishman and giant hybrid.
 * To Love Ru has a romance between a human (Rito) and at least two alien girls, Lala and Run.
 * In Ghost Sweeper Mikami Yokoshima goes after anything with a good looking female form. ghosts, robots, demons, dragon gods, wolves, foxes, etc.
 * Dragon Half is about a half-dragon Mink in love with Dick Saucer, a popular dragon slayer. Princess Vina is Mink's main love rival and a slime-half.
 * Otome Youkai Zakuro deals with the relationships between a trio of human males and half-Kitsune females in an interspecies military unit in Meiji-era Japan.
 * Technically, Neon Genesis Evangelion might count. Rei and Shinji because Rei is a (vat-grown) human-Angel hybrid. The Squee ending of Rebuild 2.0 only reinforces this: Rei previously states that she feels "warm and good" around him (though it's unknown if it's genuine attraction or ), then in the end he triggers Third Impact to save her from Zeruel. Shippers, rejoice. Also, if he meant what he said, Kaworu is a full-blood Angel who has the hots for Shinji (and he was briefly shown hitting on Rei who wasn't really cooperative).
 * Bondage Fairies: Mmm... insects.
 * In Nagasarete Airantou, there is only one male on the whole island, so most of the young girls are in his Unwanted Harem, except for two. One of them is Mikoto, who crushes badly on other girls, especially Rin, and Mikoto's sister Kunai, who is attracted to...a penguin.
 * Himawari gives us Yusura and her boyfriend Yonezawa, a kappa. Thankfully, he is the cute, friendly, anime-version of a Kappa, not an organ-sucking river monster. And they both love cucumbers...
 * There's two cases of this in Animal Yokocho. Issa the panda sometimes wants to be the main character Ami's boyfriend, and Kenta the bear and Ami's friend Ku are openly in a relationship. Sure, Issa and Kenta are technically stuffed, but they're obviously sentient...
 * This is jokingly implied to happen between spacefarer Hikari and her pet ferret Einstein in the Hentai Alien From the Darkness, at least in the English dub.


 * In Spy of Darkness, a terrorist named Vanessa Hammer steals a biological weapon known as the "Sex-beast" from a high tech government laboratory, mainly because she was overwhelmed by desire after seeing what the creature did to a young lab tech unfortunate enough to be locked in a room with it. From then on Vanessa allows it to have its way with her until she is satisfied, after which she makes it switch to the numerous women she helps it kidnap.
 * The hentai anime EL features a romance of this kind between El and.
 * Chihiro and Haku in Spirited Away, human and.
 * Celty and Shinra from Durarara, the former being a Dullahan (a headless Irish death fae) and the latter being a somewhat eccentric human scientist.
 * The Cat Returns is a Japanese animated film directed by "Hiroyuki Morita", produced by "Studio Ghibli". A girl called Haru, a quiet, shy, and unassuming high school student who has a long-suppressed ability to talk to cats. One day, she saves a darkly colored, odd-eyed cat from being hit by a truck on a busy road. The cat turns out to be Lune, Prince of the Cat Kingdom. In return, the cats shower her with gifts of catnip and mice. She is then offered the Prince's hand in marriage. Her mixed reply is taken as a yes. Immersed in desperation over this unwanted development, Haru hears a kind, female voice, which tells her to seek out the Cat Bureau. Haru meets Muta, a large white cat the voice told her to seek for directions, who leads her there to meet the Baron Humbert von Gikkingen(or just "Baron" from Whisper of the Heart), and Haru discovers her true self and tells the Baron how she has a little crush on him.
 * In Wicked City the human Renzaburou and the demon Maki eventually develop feelings for each other and consummate their love near the end of the movie.
 * Arashi no Yoru Ni is essentially a series of books and one anime film based around a goat and a wolf in love.
 * Subverted in Eve no Jikan with the couple Koji and Rina; each believes the other to be human, but they are both revealed to be androids.
 * In Nerima Daikon Brothers, Ichiro and Yukika are both a little too into the panda, Pandaikon. And pretty much everyone wants Ichiro, and I mean EVERYONE, human and animal alike.
 * Keroro Gunsou, aka Sgt Frog has many interspecies interest though it is one sided or unrealized love. The most prominent crush in the series is "Giroro" the reddish alien frog (called Keronians) to the human (referred as pekoponians) "Natsumi". the keronian, hard-boiled, combat specialist Corporal Giroro who wants to invade Pekopon (Earth) is deeply in love with the tomboyish Pekoponian school girl Natsumi (everyone knows this, except Natsumi....) who is considered an obstacle for the invasion. “She’s the girl of their nightmares…& the girl of his (Giroro’s) dreams.” There is also Angol Moa/Mois, a ditzy humanoid alien girl from the Angol tribe who has a deep crush on Keroro (an alien keronian from the 58th Planet of the Gamma Nebula). “I’ve kissed enough princes to deserve my frog…” Sergeant Major Kululu has this thing of watching Aki (the hot mom of Natsumi & Fuyuki) shower & seems to have a creepy thing for her, though she does not seem to mind him & thinks he is a cool addition.
 * In To Aru Majutsu no Index, one member of Touma's Unwanted Harem is Kazakiri Hyouka, an artificial angel.
 * Pet Shop of Horrors: If you've had sex, it was with an animal demon in temporary human form.
 * The Mazinger trilogy (Mazinger Z, Great Mazinger and UFO Robo Grendizer) has several examples from romances between humans and humanoid aliens: Duke and Hikaru, and . And the you have . Both of them are aliens but they are from different species -and born in different planets-.
 * Kazuya and Erika from Daimos. He is human, she is a alien Winged Humanoid, and both of them are Star Crossed Lovers.
 * Death Note has, though in both cases the attraction is entirely emotional and entirely one-sided. And then Rule 36 of the Death Note averts this trope entirely.
 * Death Note Rule XXXVI: "There are male and female gods of death, but it is neither permitted, nor possible for them to have sexual relations with humans. The gods of death also cannot have sex with each other."
 * Death Note Rule XXXVI: "There are male and female gods of death, but it is neither permitted, nor possible for them to have sexual relations with humans. The gods of death also cannot have sex with each other."