Split Personality / Anime & Manga

• Air Gear: The perky, happy Akito has another personality, the violent and curse-spewing Agito, who was created after his older brother locked him in a cage and forced him into fighting against other AT users. Who's in charge can usually be indicated by his Eyepatch of Power (Agito's is over the left eye, and Akito's is on the right). The manga, however, went even further and introduced a third personality named Lind, who seems to be more mature and worldly than the two of them.
• From Akuma no Riddle, Mahiru/Shin'ya Banba. By day a Shrinking Violet, by night an aggressive psycho.
• Angel Sanctuary: An interesting subversion with Alexiel and Setsuna. Setsuna is (currently) the dominant persona while Alexiel steps occasionally as his Superpowered Badass Side whenever he's in over his head. Although each has a completely different character, Setsuna still occasionally echoes some of Alexiel's words and personality, proving that they really are the same person deep down.
• Attack on Titan: Eventually revealed to be true for Reiner Braun, who is also the Armored Titan who broke down Wall Maria. It's played a bit more realistically in that it developed due to trauma, in this case the extreme guilt of having broken down the Wall and unleashing the Titans on who he now realizes are ordinary, innocent people, and the two personalities are not two distinct identities but rather two aspects of the same person. He labels one "the Soldier" (the loyal member of the army within the walls who fights the Titans), and the other "the Warrior" (his true personality).
• Ayakashi Triangle: The Ayakashi Medium has gone through Reincarnation numerous times. All of her past lives were rejected by humans due to her extraordinary power. In her most recent previous life, she was used as a Human Sacrifice by the Ungrateful Townsfolk. The trauma caused part of herself to split and become a Literal Split Personality seeking to Kill All Humans in Revenge. In her next life, her Past-Life Memories left her a Broken Bird. She eventually got the idea to create a new personality free of her previous memories to give part of herself a normal life, resulting in a total of three personalities. The dominant personality, Suzu, hopes to reconcile with her separated personalities, combine together, and unlock their full power for a common goal. Ultimately, they do so for the Final Battle, after which the other two leave Suzu's body indefinitely, but leave their power with her.
• Black Lagoon's favorite Creepy Twins, Hansel and Gretel, crank their typical Nightmare Fuel on this trope and share split personalities with each other. They could decide themselves who wanted to be Hansel and who wanted to be Gretel at the time, to the point that there is Wild Mass Guessing as to which one was actually which at any given point during their story arc. There are even some that believe that both were the same gender, as to which that is left up to debate.
• Bleach: The swords used by Shinigami, Zanpakuto, reflect their wielders' nature in weird ways. It's possible, though extremely rare (as in, only two canon examples) for a Zanpakuto to have two spirits inhabiting the weapon. The primary example is Ichigo's Tensa Zangetsu, which is split between the "Hollow Ichigo" spirit (the true Zangetsu that reflects Ichigo's power as a Shinigami) and the "old man in black" spirit (the reflection of a piece of Yhwach trying to take possession of Ichigo's power). Usually, when Ichigo goes into his Mental World, the two spirits share the same body, which changes form depending on who's in control. However, in the final arc Ichigo learns his Zanpakuto's, and by extension his own, true nature and accepts both as extensions of himself. The autonomous Zangetsu spirits are never seen again, implying a Split-Personality Merge with each other and their wielder.
• In the Hentai manga series Bondage Fairies, the fourth manga — Extreme — introduces Urushira, an old flame of Pamila's. By day, she's a sweet and caring doctor. At night, her other personality — a nymphomanic Psycho Lesbian who is oh-so-very Yandere over Pamila — takes over. And when she wakes up the next morning, she doesn't remember a thing that her dark side did last night.
• In Cardcaptor Sakura, Yukito Tsukishiro turns out to be the "disguise" of Yue, Kero's counterpart. Yue changes into Yukito on purpose, but Yukito has no idea Yue exists and cannot remember anything that happens to Yue. He doesn't know that his comically large appetite is due to his actually eating for two (the other being a powerful magic-user). He later comes to realize what goes on when Touya gives his powers to Yue so neither he nor Yukito would disappear.
• Motoko in Change 123 has three split personalities named Hibiki, Fujiko, and Mikiri — collectively known as HiFuMi (1, 2, 3) — that materialize whenever she's in danger. These split personalities come from her Training from Hell under three different adoptive fathers. Changes in hairstyle, muscle structure, and cup size come with it,^note Also, in the colored promotional panels, their eyes and hair usually have different colors. (See "Color-Coded For Your Convenience" item in the manga's "Characters" sub-page.) along with martial arts styles — each personality, other than Motoko, are martial arts masters in a single specific field.
  A 5th personality emerges at one point called Zero. Zero represents all of Motoko and HiFuMi's negative emotions, and is very unstable — oh, and she has all the other personalities' martial arts expertise, at the same time, and is super strong, to boot. Later, it's discovered that Zero is actually Motoko's first split personality, her "Mr. Hyde", created when she forcibly locked away her anger (because she superstitiously believes that her anger killed her mother).
• In Classi9, Franz Liszt's personality changes completely when he touches the piano. Chopin says he looks "possessed", and it turns out Demon!Liszt is a separate person, or at least sees himself as such. Regular!Liszt usually doesn't remember his performances and is extremely sorry for the damage his alter-ego has caused even if he has no idea what happened, whereas Demon!Liszt is aware of Regular!Liszt and his past actions.
• Count Cain reveals in its Wham Episode that the Riff that all the characters knew was actually a fake personality, created by the Delilah Organization. The real Riffael was an awful, cruel man, and when he's reawakened, he immediately betrays the protagonists.^note Many readers suspect that this was partly The Tower being duped like he was over the zombie thing, and that while 'the original' wasn't the greatest guy, he was a more normal human being than either of his halves. Thus, Riff cutting his wrists in guilt over surviving his family, even though he doesn't remember that he set the fire, is an enaction of Riffael Raffit's self-hatred that he was too proud to express and The Tower doesn't even feel anymore.
• Tyki Mikk of D.Gray-Man has commented how having a light side and a dark side makes life more fun. He can be a perfectly ordinary, personable man, but is also a tremendous sadist and has killed at least five Exorcists, including one of the Generals. Most of the other Noah have similar Split Personalities, albeit somewhat less extreme.
• Shiro from Deadman Wonderland seems to have a violent, deadly Split Personality created to deal with her Dark and Troubled Past. This is revealed to be just an act. In reality, Shiro's violent antics were acts of jealousy toward Ganta for being able to live the privileged life she never had. Her actions as the Wretched Egg were also meant to strengthen Ganta up so he could eventually fulfill her wish by killing her.
• In episode 12 of Death Note, Light agrees to place himself under surveillance due to the possibility of "another him killing people in his sleep". While Light is, in fact, unknowingly Kira, he and the SPK are wrong about how it works — he's currently under a Memory Gambit, and the only true difference between the two is that Kira has the Death Note.
• A downplayed example in Demon Slayer: Kimetsu no Yaiba. Zenitsu at first glance is cowardly and whiny; however, the sleep trance he developed for unconscious combat is pretty much the ideal version of himself that Zenitsu dreams, but thinks it is impossible, of becoming. In later events, when Zenitsu starts talking during his trance, he is shown to be very brave and just, fully in tune with all the results of his Thunder Breathing training; in this state, Zenitsu remembers everything that happened while he was awake; meanwhile, the normal Zenitsu does not remember what he did during his trance, furthering his own perception that he is weak and worthless. In truth, awake Zenitsu and trance Zenitsu are the same person, as it's only that during sleep Zenitsu removes all of his immediate flaws, which eventually reaches the natural conclusion of Zenitsu forsaking the need of his trance, becoming a hero fully aware of himself.
• Detroit Metal City contains mild-mannered Negishi , whose alternate personality Johannes Krauser II is the badass and feared leater of a Death Metal band.
• On Dragon Ball, the character Lunch or Launch (depending on the translation) would go from a sweet, naive, blue-haired (or black-haired in the manga) girl to a hot-tempered, gunslinging, criminally-inclined blonde and back again whenever she sneezed, which is surprising often. This even gets weaponized when the Red Ribbon Gang arrive.
  • In Dragon Ball Fighter Z, the Third Arc reveals that this is the case for Android 21. The first two arcs portray her as having a soft and naive facade, but it is revealed that she actually has an evil half that fuels her insatiable hunger that is slowly taking over. Part-way into the arc, they split into two physical beings, freeing the base Good 21 but unleashing the super-powerful Evil 21 unto the world.
• Nyu/Lucy in Elfen Lied. One has the mental capacities of a small child, the other's an insanely powerful killer out to take out a significant portion of humanity. It turns out that Kaede is actually a fairly neutral identity, who's just been listening to a third Omnicidal Maniac personality that wants to end all life. It seems that most, if not all of the diclonii have a "neutral" personality and their inner voice that tells them to exterminate humans. Especially apparent in Nana's case, where, when pushed, she will become just as violent as any of the others.
• Excel♡Saga:
  • Parodied in one episode in which a cute detective channels her late father whenever she puts on his hat.
  • At the end of the series, Il Palazzo shows another kind of split personality, becoming possessed by his own desire to conquer. This was a definite case of a Superpowered Evil Side, along with elements of demonic possession.
  • In the manga, which had more time for these things, the split personality is more of a subversion, the only real differences being the fashion sense and preferred targets — neither are evil or good, and both are slightly insane. It's still a bit unclear how Lord Il Palazzo's personalities work in the manga: sometimes it seems that it's only a case of varying amnesia, vaguely remembering and forgetting things from his past, which shape his motives. But one consistent difference has been that sometimes he is fond of Excel and tries to get her to remember something (maybe), while other times he wants her gone. It's also unclear which personality, his caring or uncaring one, is his true personality.
• Fairy Tail:
  • The leader of the dark guild Oracion Seis is a man who goes by two titles, each representing one of his personalities. The main personality and face is Brain, an Evil Genius who has invented countless dark spells and seeks to rule a dark order. The second more powerful and more evil personality is Zero, an Omnicidal Maniac that wants to destroy everything and is acknowledged as the true "master" of the guild. Brain is so afraid of his other side that he devised a seal on Zero that can only be broken if all six main members of the Oracion Seis fall in battle.
  • If the words of Zeref are any indication, then Natsu has one of these. Specifically, his Split Personality is E.N.D., Etherious Natsu Dragneel, the most powerful demon Zeref ever created, leader of the genocidal guild called Tartaros, and who is currently sealed within his Book of Zeref, and it can only be awakened if enough "curse power" is gathered to force the seal open, or if Natsu himself opens the book.
• Fruits Basket:
  • Hatsuharu, the ox of the zodiac, who turns into 'Black Haru'. Black Haru usually comes out when he's angry, and while Haru is usually easy to get along with, no one can handle his other side.
  • There's a milder version in Kagura, the boar, who is sweet and mostly caring but becomes possessive and quite occasionally violent when Kyo is around. Either tsundere to the extreme or possibly a bit yandere.
  • Both could be considered oddly realistic takes, as well. Neither are shown to be aware of the changes, except from what others tell them (Kagura is even confused about why Kyo looked so beaten after one incident), and we've seen just what caused them to develop and triggers the changes. Haru's "Black Haru" personality developed as a result of verbal abuse and his overwhelming resentment of Yuki, and he only changes when angry (harder to achieve than it sounds). Kagura, on the other hand, switches when something threatens to expose that she's trying to love Kyo to get over her past guilt.
• Hohenheim from Fullmetal Alchemist is revealed to suffer a sui generis, mindblowingly over the top case of this. Long story short: he is a human Philosopher's Stone; these are made out of many people's souls, so do the math. He has devoted most of his life to isolate, communicate with, and befriend each of these 536329 different people "living" within him. Fortunately, while the souls sealed inside him have widely varying backgrounds and alignments (one of them was even a Serial Killer in life), they and Hohenheim all have one thing in common: they all want revenge against Father, who murdered all of them and sealed them inside Hohenheim.
• Nobara Ibaragi in Gakuen Alice has some sort of split personality — one personality adores and wants to protect Mikan, and the other does whatever her evil 'teacher' tells her to do.
• Gamaran Shura has Genra, member of a special corps of powerful assassins and living weapons known as Genkai Tenpei. Genra is normally calm, controlled and analytical and sports a face-covering cloth with a paper talisman on it. When he removes the mask and a massive weighted cloth from his person he takes a much wilder and more brutal personality he calls "Zenra", which is a much deadlier in combat.
• Gintama: It is revealed late in the manga that Yoshida Shoyou, Katsura's, Takasugi's, and Gintoki's teacher was the split personality of an unmamed Japanese Mutant, whose mutation gives him a Healing Factor and longevity by absorbing and storing large amounts of Earth's Altana. But the decades of constant persecutions and deaths resulted in him creating multiple personalities to cope. He ultimately becomes a government assassin named Utsuro, creating the future Elite Mooks the protagonists fight throughout the manga with Shoyou himself being born during this time. Shoyou is the White Sheep of the personalities created from their collective weariness of death and killings and desire to do something positive, ultimately succeeding for a while. The present Utsuro, implied to be the original personality, is just as weary, even more so, but has become a Death Seeker Omicidal Maniac tired of the pain, suffering and foolishness all life, both humans and Amanto, go through. And it's this personality that nearly succeeds in destroying everything until the protagonists stop him, twice.
• In GTO: The Early Years, Nagisa responded to Akutsu's abuse of her by making a split personality, Yasha, to protect her from the trauma. Yasha is a Superpowered Evil Side and Enemy Within who loves Akutsu, and tries to kill Ryuji and Eikichi, while Nagisa's normal personality is nice and sweet.
• Examples from the Gundam franchise:
  • Mobile Suit Gundam 00:
    • Allelujah Haptism has a rather psychotic other half that he calls Hallelujah.
    • Additionally, Marie Parfacy has one named Soma Peries. Soma "goes to sleep" indefinitely in the second season and Marie returns to be the one in control.
  • Lady Une of Mobile Suit Gundam Wing developed split personalities out of her love for her boss Treize, one a cold-hearted, calculating Colonel Badass, the other a kind, soft-spoken peace advocate. She has a few moments of near breakdown before being shot roughly halfway through the series and remaining comatose until the final arc. The coma apparently gives her time to resolve her issues, and when she wakes up she has Iron Une's military and strategic skills and Saint Une's compassion and desire for peace. Her glasses act as a trigger. Once she puts them on, you're guaranteed to see her order somebody's death.
• Hanaukyō Maid Team. The maid Grace/Cynthia has two personalities: Grace (highly intelligent and abrasive) and Cynthia (sweet, childlike, and mute).
• Yumie Takagi, berserker soldier of the Iscariot Organization in Hellsing. The (not canon for the series) Cross Fire stories in the first three manga volumes involve her being brought out for various assassinations, to the dismay of her other personality, a thoroughly sweet nun named Yumiko.
• In Inside Mari the Twist Ending reveals Mari to be this. The initial set up is that college dropout and loser Komori wakes up in the body of the beautiful School Idol Mari that he had a crush on in some kind of "Freaky Friday" Flip. However it’s revealed this is all false, Mari was always Mari, she just created the Komori Mari in her head due to her dissociative identity disorder. This occurred thanks to a combination of unresolved trauma from her emotional abusive mother who changed her original name from Fumiko (who becomes a separate personality) to Mari after her beloved grandmother who named her died and general conformity of her life crushing her soul. She wanted to be Komori whom could live his life carefree and after stalking and watching him, at one point snaps and wakes up believing she is Komori. The Mind Screw is only further enhanced by social outcast girl Yori who idolised Mari believing Mari’s perception that she is someone else and falling in love with the Komori Mari who she can relate to. It’s not until the end where Mari is able to come to terms with her real self and the Komori and Fumiko personalities and says goodbye to them.
• Inuyasha has Suikotsu of the Band of Seven, who has three personalities: a kind and caring doctor who has no awareness of the other two (and is the original one), an ultra-violent killing machine who knows of the other two and despises his gentler personality, and an "in-between" personality who is aware of the others and serves the Band of Seven while remaining calmer and more rational than his bloodlusting counterpart.
• The Big Bad of JoJo's Bizarre Adventure: Golden Wind has two personalities. There's Vinegar Doppio, a strange, childlike man, and Diavolo, a cunning, violent, and paranoid mafia boss. His hair color, eyes, and size change drastically^note  Doppio◊ and Diavolo◊. Doppio communicates with Diavolo by holding random objects to his face like a phone (after hearing the sound of a phone ringing, which he himself produces). As stands are the manifestation as the user's soul, their stand is actually two stands rolled into one whose powers play off of and compliment each other. Diavolo, the dominant personality, can use both stands freely and has the stand King Crimson which can skip time up to the next 10 seconds. Doppio, the submissive personality, has the stand Epitaph (represented by a secondary face on King Crimson's forehead) which allows its user to see up to 10 seconds into the future (although Diavolo can also use this). While these stands are powerful on their own, when used in tandem they become nigh-invincible, with few stand users in the entire series having any hope of defeating them.
• Subverted in Kaguya-sama: Love Is War. (Ice), (Moron), and (Child) all appear to be split peronalities, but they are all explicitly an artistic representation of Kaguya being a Mood-Swinger rather than distinct entities unto themselves.
• In Karneval, Yogi has one which causes him to unleash hell on whoever is unlucky enough to be fighting him. His usually gold hair turns silver as an indication.
• In King of Thorn, the English translation says Alice has schizophrenia, but it later becomes clear that it's actually DID — being abused by her family caused her to develop an alternate personality called Laloo, who would take the abuse for her. After she became infected with Medusa, Laloo manifested as an Enemy Without.
• In Kotoura-san, Detective Tsukino has one, due to being bullied as a child. Her evil personality was in charge or revenge and was also the perp of the physical assaults on school girls in episode 10. With the help of Haruka, the good side is able to eliminate the evil one and she is even ready to turn herself in to pay for "her" crimes, which is refused by her superior, whom she has an apparently close friendship with.
• Irabu-sensei from Kuuchu Buranko has a total of three personalities: Stuffed Animal one, who acts silly and childish, Child one, who acts more serious and snarky, and Adult one, who is something in-between but leans closer to Animal one.
• Seijuro Akashi from Kuroko's Basketball seems to have an unnamed second personality. This is probably a result from his father demanding absolute perfection in everything he does, be it school, sports, music... When he was about to lose a 1 on 1 basketball match against his teammate Murasakibara, his second personality "the other Akashi" took over in order to ensure his victory. The "real" Akashi disappeared during that event and has only now resurfaced a few years later.
• Mahoraba's Aoba Kozue has five personalities, switching to one at random whenever she's shocked or surprised. Her eye colors change for each personality, and each personality prefers to wear her hair differently. She switches back to normal by going unconscious. While each personality is pretty distinct from the rest, they all have several distinct traits they share, particularly a liking for her crush and a major thing for umeboshi.
• MPD Psycho really drives this trope to utter extremes. Some of the multiple personalities even appear in other physical bodies, and this even when their original physical body has died. Which might make this manga a slight twist. (It's amazing what the average corporation can do while trying to bring a Not Quite Dead rock musician back to life.)
• Monster:
  • Johan is indeed a real person, but Inspector Lunge (or Runge) is convinced that he is an alternate personality of Dr. Tenma.
  • Wolfgang Grimmer, meanwhile, occasionally blacks out when physically threatened. When he recovers, everyone who threatened him is dead. He refers to the personality that takes over as "the Magnificent Steiner", after a show he watched as a child (where the title character is the superhero persona of an unknowing boy).
• Murciélago: Due to a traumatic incident, one character ends up having a split personality based off of her deceased older sister. Unfortunately for the main cast, said older sister is a terrifying swordswoman who proves to be an absolute beast in combat, even when hampered by her younger sister's weaker constitution.
• My Hero Academia: The villain known as "Twice", Jin Bubaigawara, suffered a psychotic break when he abused his Quirk, which allowed him to duplicate anything, including himself. His attempt to create clones of himself to serve as servants backfired when each one, believing themself to be the real one, killed each other, leaving Bubaigawara unsure if he is the original. Since then, he suffers fro split personalities that threaten to tear his mind asunder unless he wears a mask to make his mind "whole".
• This becomes the premise of Nanaka 6/17, once the title character's original personality re-emerges early in the story, after a Laser-Guided Amnesia period in which she reversed to her 6-years old mindset. And in the manga only, aside from the 6-year old personality, Nanaka develops in the second half of the story a second split personality, which names itself "Hiro".
• In Nanbaka, Nico is revealed to have another persona, violent in comparison, that appears when his medicine wears off.
• Naruto:
  • Zetsu is split down the middle between his two personalities. His right side is black, speaks in a deep voice, and is completely professional; his left side is white, talks in a lighter voice, and is a bit more carefree. The two halves can talk and even argue with one another and even separate into two functional halves. The black half is ultimately revealed to have been infused with the "will" of Madara prior to his death, while the white half is the original Zetsu.
  • Jugo is a cowardly person who cares about his friends with a separate personality that wants to fight and kill just for the sake of doing so. The split personality is a side effect of his bloodline but not directly linked to using its abilities.
• Nectar of Dharani: Sakra's Ambrosia has its own personality, which calls itself Shakuntala. She acts far older and wiser than Sakra, as well as with more cruelty, but seems to have Sakra's best interests at heart.
• Negima! Magister Negi Magi:
  • As of Chapter 284, Asuna seems to have developed this as a result of having her Laser-Guided Amnesia forcibly undone: one is her "true" personality from before Ala Rubra rescued her from her life as a living weapon, and the other, currently dominant, is the Asuna we've come to know and love.
  • Luna, too. Ironically, her other personality is also Asuna.
• One Piece:
  • Usopp may be developing this. When it was first introduced, "Sogeking" was an assumed name and Paper-Thin Disguise Usopp used (the reasons are complicated). Usopp acted rather differently while in his Sogeking disguise, even managing to score his first real Big Damn Heroes moment before reverting back to his old, cowardly self after circumstances changed and he was able to remove the mask. During a later fight (as Usopp), he is actually depicted mentally arguing with Sogeking. Later still:
    Usopp: [running away from Perona and Bearsy] Somebody, save me! Save me!
    Sogeking: [tackling and purifying a goddamn zombie bear] Save me, Sogeking!
  • The Dressrosa Arc gives us Cavendish and his Superpowered Evil Side Hakuba, the latter awakening whenever the former goes to sleep. It turns out that Hakuba is in fact the 'white horse' epithet that Cavendish claims, is twice as strong as Cavendish, and was responsible for all the killings that Cavendish enjoyed anyway.
  • In the Whole Cake Island arc, it's become apparent that Charlotte Pudding's recent experiences and her Dark and Troubled Past have fractured her mind and led her to develop this. After falling in love with Sanji for real, she rapidly goes back-and-forth between swooning over him and yelling death threats at him- sometimes at the same time! Luckily though, she's still cognizant enough to lend him a hand even as she lapses back into "evil Pudding".
• In the manga Othello, the shy main character Yaya switches to her alter ego, bold and assertive Nana, when she sees her reflection.
• In PandoraHearts, the Baskerville Zwei's personality was split with magic after the clan's constant shunning and the frequent Demonic Possession from her chain had gone too far, leading the girl to snap.
• The title character of Paprika, who is the dream avatar of Dr. Atsuko Chiba. Paprika is everything that Chiba isn't and secretly wants to be. And it gets better: Paprika has characteristics of both Chiba and Tokita, hinting at the former's affections for the latter.
• Paranoia Agent has a woman whose split personality (who is far more promiscuous and thrill-seeking) leaves messages for her on her answering machine; threating ones. Frightening stuff. This is actually a moment where MPD is depicted accurately. There have been recorded cases of personalities threatening other personalities — even going as far as causing bodily damage.
• In season 2 of Princess Tutu, Mytho starts to complain of "another me" being inside of him, an evil personality that quickly begins to take over more and more. Later, it's revealed that it's actually the result of one of his heart shards being tainted with Raven's blood.
• Ayase and Luca Souju of Puella Magi Kazumi Magica are a pair of Magical Girls with distinctly different powers and appearances, who manage to share one body to great effect.
• Plunderer: Licht/Rihito is a very kind soul, but after the world is inflicted with the curse of the "Count System", he has to become a cold-blooded killer in order to survive in a world that has become so degraded after said system has rotted it near-irreversibly, especially after killing his best friend Tokikaze Sonohara also unfortunately gets inflicted by this via drugs.
  Rihito: I kill enemies. I kill enemies. Kill enemies. --Kill, kill, kill, kill, kill, kill--
• In Pretty Sammy, we have Misao Amano, a Shrinking Violet schoolgirl who transforms (unknowingly and involuntarily) into Pixy Misa, the evil magical girl. However, this trope is subverted when it is revealed in episode 19 that her alter ego was in fact just the repressed aspects of her personality, so the audience was led to believe that the Pixy Misa persona was due to brainwashing when in fact Misa and Misao are one and the same.
• The Prince of Tennis' got a good one. Seigaku's Takashi "Taka" Kawamura is a kind-hearted guy whose father owns a sushi restaurant, but whenever he grabs a racket, his "burning" mode is turned on and he becomes Seigaku's top power player.
• One of Shiho's clients in Private Actress has this. As a child, an orphaned boy named Yuuto Tanabe was sexually abused by his Creepy Uncle and Parental Substitute. As a result, he created a personality named "Shuuto" that dealt with extreme anger issues coming from the abuse, and under his influence he burned his uncle's house and killed him. From then on, "Shuuto" and the original Yuuto co-existed more or less in peace, and Shuuto aka the now dominant personality shaped himself into a famous Mr. Fanservice — until Yuuto took control back and fell in love with a Girl Next Door, causing "Shuuto" to snap, fully take over their shared body and try hiring Shiho (pretending to be Yuuto and Yuuto's twin brother) to get Yuuto's would-be girlfriend away. And then it turns out there's a third personality, "Satoru", who has been lying dormant underneath the two, but wants to get this mess resolved...
• There are two characters in Psychic Squad who suffer from split personalities: Sera (due to possession) and Phantom Daughter AKA Mirage a.k.a. Yuri / The Doll, Featheris initially mistaken for one but was actually a different person or something.
• Inner Moka from Rosario + Vampire. Moka's Rosario acts as a barrier; once removed, Inner Moka comes out to kick ass.
  • Also an inversion of the usual way this trope plays out: instead of a more emotionally normal person developing a more aggressive, jaded or practical persona to handle parts of their present circumstances they aren't emotionally equipped to endure, Inner Moka was the original personality. "Outer" Moka is an intentional artifact of the Rosario, designed to protect her from the ultimately self-destructive outcomes of her natural tendencies by her mother, whose own personality forms the basis for Outer Moka. This is somewhat less true or relevant in the anime.
• Gemini Saga, from Saint Seiya. The specifics are never made terribly clear (i.e we don't know exactly how it developed and came to exist), but it takes hold of him and causes him to murder and impersonate the Pope (not, not that Pope) for a number of years and generally act like a self-entitled asshole.
• Sayonara, Zetsubou-Sensei:
  • Kaere Kimura has a split personality that contains an aggressive, lawsuit-happy Gorgeous Gaijin persona and an over-the-top Yamato Nadeshiko persona. She apparently has even more personalities which depend on what country she is in.
  • SZS managed to pull the inverse of this: one personality split among many girls, thanks to Fuura being Dead All Along and her organs going to the girls in her class.
• Lain, the main character of Serial Experiments Lain, seems to have several as the series progresses: shy, schoolgirl Lain, a very famous "Lain of the Wired" who's arrogant and powerful, and a manipulative and sadistic Lain. It turns out that there are an endless number of possible Lains, as each and every person's perception of Lain, and each concept of Lain that arises via Memetic Mutation in the Wired, becomes another one of her facets. Eventually, though, they undergo a Split-Personality Merge into a kind-hearted, but extremely powerful, Lain.
• SD Gundam World Heroes stars Wukong Impulse Gundam, who's based on both Sun Wukong and the ZGMF-X56S Impulse Gundam, the latter of which had the Silhouette Packs. To represent them, they were made into two other personalities residing within Wukong, Sha Wujing Silhouette and Zhu Bajie Silhouette, who incidentally are also based on two of Sun Wukong's friends, Sha Wujing and Zhu Bajie.
• Sgt. Frog:
  • The "Other Momoka". Momoka appears sweet and harmless at first, but she hides an extremely jealous and possessive side that occasionally comes out when a perceived "rival" for the object of her affection appears.
  • Momoka's mother turns out to be the same way, except she prefers to let her aggressive side be the default; this is the reason she doesn't live with her loved ones.
• In Sonic the Hedgehog, Sonic is one to Canon Foreigner Nicky Parlouzer, who turns from a Nervous Wreck to a Superpowered Alter Ego who protects Hedgehog Town. Nicky, however, has Alternate Identity Amnesia and isn't aware of Sonic's existence.
• Yamamoto Jun from Special A turns from a relatively shy guy to a Casanova whenever he is kissed by a girl. Later on, it seems to be when a certain girl just looks at him.
• Another classic Hentai manga, Super Taboo, had Yuu Sakagami, a guy who had two distinct personalities. The first was his normal personality, and was governed by Reason. The other, his more evil and lustful side, was governed by instinct, and came out when one of his incestuous family members made him horny. Eventually, the Instinct side became more violent and sadistic, leading to Yuu hurting his sister Eri, and his mother took action — his father was the same way, and it turned him into a sadistic pervert that she couldn't live with. Eventually, the two sides had it out in a final showdown, and Reason ultimately won.
• In the Trigun manga, we have Livio and his Superpowered Evil Side, Razlo, which he developed as a child. His very distinct personalities cause him to be the last two members of the Gung-Ho-Guns.
• Uta No Prince-sama Maji Love 1000%: Natsuki is typically oblivious and, to an extent, airheaded. Despite his positive outlook on life, he gets discouraged quite easily. "Satsuki", his alter ego per say, comes out when Natsuki's glasses are removed. Satsuki is harsh and combative, rumored to have put 50,000 people in the hospital for angering him.
• Maki Kisaragi from W-Change!! is a Girly Girl who likes sweets and handycrafts, and who has a dark split personality that is violent and loves to fight.
• Examples from the Yu-Gi-Oh! franchise:
  • Dark Yugi in Yu-Gi-Oh! is initially presented as one of these, before it is revealed that he is actually the spirit of an ancient Egyptian Pharaoh. The same goes for Dark Bakura, who is actually the spirit of an ancient Egyptian Thief/Tomb Robber combined with an Eldritch Abomination, but not Dark Marik, who is a more traditional split personality caused by childhood trauma. Ironically, Yugi's GX successor in the anime-only spin-offs is a true example.
  • Sora from Yu-Gi-Oh! ARC-V, maybe. Usually he's a nice guy, something of a bumbler, and unsure of his abilities. When actually dueling, however, his attitude turns far more serious and malevolent, his appearance becoming menacing and his speech pattern sounding sociopathic, seeming to show sadistic pleasure in hurting his opponent. Possibly, this is due to his attachment to the Fusion Dimension.
• Shinobu Sensui in YuYu Hakusho was a lawful yet pure and innocent young man before encountering the Black Book Club, rich men who tortured demons for fun. He couldn't bring himself to kill humans (as opposed to demons), and so developed another personality to do the dirty work. Over the years, he developed six alternate personalities, switching between them depending on the situation (I.e: he used the Magnificent Bastard "Minoru" to recruit his followers and pull strings, then when Yusuke managed to hit him he switched to the Ax-Crazy "Kazuya"). Each one has a different level of power; the original one, Shinobu, is the most powerful of them all...and is still an innocent, as he let the others do the dirty work.
• Jamie Hemeros in Zoids: New Century develops a cocky ace pilot alter-ego named Wild Eagle who takes control during battles every now and then. Although popular opinion seems to suggest that this happens when Jamie breaks the sound barrier in his Zoid, Wild Eagle actually seems to appear only when Jamie gets overly stressed out in battle.