[[DeathNote http://tvtropes.org/pmwiki/pub/images/deathnote3601LG.jpg]]
[[caption-width:330:Misa! Quit messing with the [[IncrediblyLamePun Christmas Lights]]!]]


Oni is a Japanese word which roughly translates as "[[TheLegionsOfHell demon]]" or "[[OurOrcsAreDifferent ogre]]", and represents a creature from Japanese mythology. The original oni were large, brutish creatures, often illustrated wielding large metallic clubs. Those that weren't in hell tormenting sinners roamed the remote, mountainous areas of Japan, where they often carried people off to be eaten, only to be defeated by valiant heroes or holy monks. ([[http://x9d.xanga.com/c4e013e121533171161666/w92990104.gif Here]] [[http://x00.xanga.com/f5fc2a0179533171161099/w129910357.gif are]] two traditional-style depictions of oni). Later, other meanings and connotations would grow around them, including as guardians of people or towns, which would mount oni figures on the walls to ward off evil spirits (much like gargoyles in The West), and parades and processions would be led by men dressed as oni. (Obviously ''not'' as the savage, loincloth wearing version.)

Differing sets of personalities are attributed to red oni and blue oni, which have often come to be the personalities of many a protagonist/antagonist combination, or that of a pair of rivals.

The red oni is associated with passion, wildness, defiance and fire. A red oni character is often more brawny than brainy, enthusiastic, determined, and filled with a zest for life. He is also much more likely to break conventions and rules than his counterpart. Often an IdiotHero or, in more mature pieces, a cousin of the BoisterousBruiser, and most likely to be HotBlooded. When a villain, a red oni may turn into a BloodKnight. Whereas his blue counterpart puts a lot of focus onto higher goals, causes, or [[HonorBeforeReason codes of behavior]], the red is primarily [[TheMcCoy concerned with people]]. Say something nasty about their country or cause, they'll usually shrug or laugh it off. Say or do something nasty to their [[{{Nakama}} closest friends]], and you've guaranteed yourself [[RoaringRampageOfRevenge a world of pain]].

The blue oni is an opposite in most ways -- more intellectual, proud, traditional, cultured (sometimes more spiritual, although that's not guaranteed), and associated with water. Blue oni personalities are often respected by others, but also likely to puzzle or confound their peers because they are difficult to read and have a mysterious quality to them. Personality subtypes include TheStoic, TheSpock, TheQuietOne and AloofBigBrother. (Pride, aloofness, or social ineptness also means they frequently [[CanNotSpitItOut have trouble spitting it out]], whatever "it" may be.) It's worth noting that while blue types appear tremendously calm and composed, sometimes this is just the surface, and scratching that facade may show that they are, if anything, wound far too tight beneath their calm and unemotional appearance. (This is particularly true of the villains). Villainous blue oni tend to be extremely ruthless, ready to do or sacrifice anything (and often anyone) to accomplish their goals. See KnightTemplar and WellIntentionedExtremist.

The two are almost always forced into close contact, either voluntarily or by some outside social or legal reason such as being members of the same family, class, dojo, soldiers together in TheSquad, etc. Despite their wildly different personalities and philosophies the two often have either the same (or related) professions and/or skills. This of course gives them something to butt heads about, since they will also often have vastly different ways of going about whatever it is they're competing over and each will insist that his way is the best.

Because DumbIsGood, a red oni is more likely to be the lead character, but the variations are many. Sometimes the two are both leads on an equal standing, sometimes the blue is more of TheSmartGuy or TheLancer to the red lead. The relationship can also vary wildly, from close brothers and friends to bitter rivals or enemies. One thing that is sure is that regardless of how big a cast is, when these two are in it, they will be magnetically drawn to each other. Their personality differences set up chances for both great drama and great comedy in playing off each other. No matter how many other rivals and counterparts these two might have, or if a bigger BigBad comes along, nothing else will equal the chemistry between these two.

In a show where it's relevant, differences in fighting style will be something like TechnicianVersusPerformer.

Compare OutsideManInsideMan, OddCouple, CastCalculus (for the evolution of the Red/Blue dynamic through various numbers of ensembles) and OrderVersusChaos.

See also PinkGirlBlueBoy, ActionDuo.
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!!!All examples are listed in the red-then-blue order unless otherwise specified:

[[foldercontrol]]


[[folder:{{Anime}} and {{Manga}}]]
* Mugen and Jin from ''SamuraiChamploo'' are not only prime examples of this, but also are always dressed the respective colors too. Mugen is full of energy and reckless passion without direction or purpose (or the brain power to put it to use), while Jin is practically unable to feel passionate about anything or form attachments to anyone. Fortunately, [[CharacterDevelopment they get better]].
* The [[FullMetalAlchemist Elric]] brothers Edward (red) and Alphonse (blue). Ed is typically more impulsive quick to anger, and wears a red coat, while Al is a more collected GentleGiant who typically has to restrain his older brother, and [[strike:wears]] is a cool gray suit of armor.
* Shinji Hikari (red) and Richard Lancolot (blue) from SpaceMusketeerBismarck, although the people behind Saber Rider don't want you to believe it.
* Kazuma and Ryuho from the ''{{S-Cry-ed}}'' anime.
* [[HotBlooded Inuyasha]] and [[AloofBigBrother Sesshoumaru]] from ''{{Inuyasha}}''.
* An arguable case is Ogami Itto and Yagyu Retsudo from ''LoneWolfAndCub''. Although Itto doesn't have the not-so-bright or tasteless qualities of many red oni, he is driven to incredibly reckless behavior and horrid deeds by a passion for revenge, while Retsudo prefers being the puppetmaster and using [[DeathTrap traps]], {{mooks}} and the like. Along the way, he sacrifices [[MoralEventHorizon an appalling amount of men and his own children]] in his attempts to stop Itto.
* Light and L from the ''DeathNote'' anime series are often shaded in red or blue to reflect this, although personality-wise it doesn't ''quite'' apply, since aside a few times that Light gets riled up after his cause is challenged, ([[spoiler: and just before his death]]) both Light and L tend towards being brainy, cold blooded types. This theme is also used (and generally played much straighter) with Misa and Light, Light and Near, Mello and Near, and even Misa and Takada.
** In [[ButtMonkey Matsuda]]'s DayInTheLimelight episode he is shown with the same lighting effects, but yellow.
* Goku and Vegeta of ''DragonballZ'' exemplify this trope to a point where it could be named for them.
** You sure about that? They both seem like RedOnis to me. Goku in that he's an {{Idiot Hero}}, is concerned about people, and is emotional about everything. Vegeta in that he's a {{hotblooded}} berserker. Perhaps Goku and Piccolo are closer to RedOni, BlueOni?
*** [[CharacterizationMarchesOn Although it's hard to remember now]], but when Vegeta was first introduced he seemed like a coldblooded and heartless killer, one who seldom emoted more than wearing a PsychoticSmirk when killing someone. It wasn't until Goku proved himself an equal, if not superior in fighting ability, (something that goes directly against Vegeta's pride, the Saiyan traditions and culture he prizes so, etc) that Vegeta starts going off the deep end. Even then, it's worth noting that in the description it does say that (especially for villains) the calm, unemotional face of a Blue can just be a facade, and conceal a lot of intensity and even craziness right below it. (Oh, and Piccolo is definitely a Blue type as well.)
** Another example from ''DragonballZ'': Goku encounters a literal red and blue oni in the first season. It's inverted, as TheBigGuy bruiser is a blue oni (who gets beaten quickly in a contest of strength), while the faster and more clever red oni challenges Goku to catch him, and spends half the episode dodging the hero.
** Also, Vegeta was part of a completely evil oni team when paired with the BloodKnight Nappa.
* On the same side, but Ryoma and Hayato from GetterRobo definitely fit. Ryoma's a heroic burning-sense-of-justice type(well, most of the time...), while Hayato is a cold-blooded loner. This is taken into extremes in ''Getter Robo G'', where Ryoma's Getter Dragon is red and Hayato's Getter Lyger is blue!
* Naruto and Sasuke of ''{{Naruto}}'' (Complete with the colors of their clothing and demon forms). In the third opening of ''[[OddlyNamedSequel Naruto Shippuden]]'', "Blue Bird", the pair are shown against a red-and-blue background. Unusually, Naruto has wind-based powers, while Sasuke's are fire-based.
** ''Naruto'' [[GeodesicCast loves this trope.]] Pretty much every team has the two guys as this with the girl making it a PowerTrio. Other Red Oni / Blue Oni pairs include Lee and Neji, Guy and Kakashi, Kiba and Shino, and arguably even Kankuro and Gaara and Choji and Shikamaru to an extent.
** The color scene is inverted with Akatsuki partners Itachi and Kisame, the former being a cold, calculating AloofBigBrother with [[RedEyesTakeWarning red eyes]] and with several fire jutsus, the latter being a BloodKnight that specialises in Water Jutsus and has the blue skin of a shark.
* There are numerous cases that could be argued from ''{{Bleach}}'': Ichigo and Ishida, Ichigo and Byakuya, Renji and Byakuya, Ishida and Renji, Grimmjow and Ulquiorra.
* RurouniKenshin has Sanosuke and Kenshin, who are even cast in their respective colored lights during their first battle. After losing Sano becomes TheLancer.
* In ''FruitsBasket'', calm, blue-eyed, grey-haired Yuki and temperamental, red-haired, red-eyed Kyou are cousins and rivals in love, martial arts and to some degree even social life, each one envying the other's abilities in dealing with people.
* Zenon and Shien, the two gods that appear about halfway through ''Gensou Maden {{Saiyuki}}''.
* A classic female example: Kei ([[FieryRedhead Fiery]] DarkSkinnedRedhead, GenkiGirl and/or [[{{Bokukko}} tomboy]]) and Yuri ([[PaleSkinnedBrunette Pale Skinned]] [[YouGottaHaveBlueHair Blue-nette]] YamatoNadeshiko with {{Kawaiiko}} tendencies) from ''DirtyPair''. Many of the LovelyAngels teams who [[SpiritualSuccessor followed in their footsteps]] share a similar Red Oni-Blue Oni dynamic.
** The titular duo of ''FutariWaPrettyCure'': Nagisa is the lacrosse-playing tomboy who wears the black and red costume, Honoka is the intellectual one in the white and blue dress. At one point they even fight a pair of red and blue Oni just to drive the trope home.
*** And of course their [[{{Expy}} Expies]] in ''Splash Star'' fulfil the roles as well.
** ''KiddyGrade'' has Eclair (red oni and boisterous ActionGirl) and Lumiere (blue oni; calm, [[TheSpock logical and cultured]] {{Technopath}}), and they both wear colors to match.
* Zatch and Brago from ''ZatchBell''. Also, Zatch [[spoiler:and his EvilTwin Zeno]] later on in the series. The former is a kind, but childish boy who wishes to be friends with anyone he meets, while the latter is a cold, manipulative person who hates humanity and bears a grudge towards Zatch, [[spoiler:though this is only because Zatch received the ''Baou'' power instead of him.]] Their owners and even the color of their books reflect this as well.
* Asuka Langley Soryuu and Rei Ayanami from ''NeonGenesisEvangelion'' also satisfy this trope, although more in the "rivalry and/or mutual loathing" sense; that doesn't stop StudioGainax from pairing them up in merchandising, though.
** Note that their 'theme colour' is inverted in their eye colour: Rei is blue-haired with red eyes, Asuka is a redhead (or a blonde in the manga) with blue eyes. This arguably reinforces their contrast and even complementarity.
** Their mecha are, however, all red and all blue respectively, and explicitly compared to oni in concept and design just to be obvious.
**If you look at the colors of the mecha and plug suits, Shinji appears to be the blend of the two: not a hot-blooded glory hound but not a heartless machine completing the PowerTrio.
* ''YuYuHakusho'' has ''literal'' blue and red oni -- the blue oni are the bureacrats in the Spirit World, while the red oni are security. With the protagonists, Yusuke and Kuwabara are both brash and eager, ready to throw themselves at a challenge, while demonic protagonists Hiei and Kurama are far more calculating and keep much cooler heads about them.
* {{Digimon}} season 2 has the high-energy, somewhat brash gogglehead Daisuke paired with introverted intellectual villain Ken, who pulls a HeelFaceTurn halfway through the series. While enemies, they repeatedly face off; while allies, they find out that their digimon can combine into a much stronger digimon, linking their characters even more than before. Furthermore, Daisuke felt a kinship with Ken before they learned that he ''was'' a villain, and, of all the other heroes, was the most sympathetic toward Ken during the time between repentance and alliance. Oh, and on the Blue Oni quality of "pride and aloofness": After his repentance, Ken spent a long time apart from the hero group, trying to "clean up his mess" in his own way, and worried that even if he tried to join up, they wouldn't accept him.
**In the first half of the season, T.K. was the BlueOni - smarter, more level-headed and rational than Davis. With Ken's arrival, T.K. sort of became the third banana though.
** Just 02? Let's see, in the first [[DigimonAdventure Adventure]], we have the main character, Taichi, who Daisuke is an {{Expy}} for, and so they share a lot of personality traits (albeit Taichi's are toned down a little), and AloofBigBrother [[TheLancer Lancer]] Yamato, who spends most of his time [[BigBrotherComplex trying to figure out what will keep his younger brother safest]]. While Taichi is unrestrained emotionally, Yamato is more prideful and tends to get embarrassed quickly at activities that lower him down to Taichi's level. Taichi is associated with the color orange (at least it's close to red), and Yamato with the color blue.
***A way in which this is inverted is that in this case it's ''Tai'' (the RedOni) who is more concerned about big picture and the goals, while ''Matt'' (the BlueOni) is more concerned with people and making sure everyone's happy - Matt has even accused Tai of having ''ice in his veins.''
** Just [[DigimonAdventure Adventure]]? Masaru and Touma in ''DigimonSavers'', there are specific episodes built around their might vs. mind clashes, and Touma seems particularly afraid of losing his coolness and intelligence in the face of Masaru's determination and charisma. Nanami taunts him with the fact that he didn't defeat with his prided logic and calculations; he beat her by charging at her head on, Masaru-style, and this seems to disturb him. Their [=DATS=] uniforms (red bodysuit with blue jacket for Masaru, blue bodysuit with blue jacket for Touma) reinforce this... heck, there's an absolutely hilarious ImageSong dedicated to them (and Agumon and Gaomon) explaining why their personalities and methods clash, but they're still the greatest team... right?
** [[DigimonFrontier Takuya and Kouji]] also have something of this dynamic, as do [[DigimonTamers Ruki and Takato/Jenrya]].
** In short, all seasons of Digimon invoke this trope.
* Duck (or Ahiru in the Japanese version) and Fakir from ''PrincessTutu'' follow this trope very well. Duck has orangy-pink hair, and is a loud, determined, dizty klutz who cares deeply about people and wants to be everyone's friend. Fakir is a green-haired boy who is cold, seemingly prideful and anti-social. They start off as bitter rivals but later [[spoiler:discover they have the same goal -- to help and protect Mytho -- and end up becoming awkward partners. In the second season, Fakir develops a crush on Duck and the two become even more closely associated.]]
* Subverted by the ''LastBlade'' series, where the reckless, [[ArrogantKungFuGuy arrogant]] Kaede is wears blue, and the TroubledButCute [[TheQuietOne Quiet One]] Moriya wears red and has red hair.
* Keroberos and Yue of CardCaptorSakura fame also qualify; [[TheStoic Blue Oni]] Yue is often cold, introspective, and seemingly totally dispassionate, while [[TheIdiotFromOsaka Red Oni]] Kero-chan is hot-headed and emotional.
* Jonouchi (Joey) and Seto Kaiba from ''{{Yu-Gi-Oh}}'' follow this trope to the letter, right down to their trademark cards.
** As do Fubuki (Atticus) and Ryo (Zane) from GX. Although, this [[{{Expy}} probably isn't entirely coincidential...]]
* In ''[[TriGun Trigun]]'' (especially on the manga covers), Vash is associated with fiery reds and poses full of dynamism while Wolfwood is associated with blue and grey tones and more static positions. Bonus points if Wolfwood also glares coldly at the reader. This is an accurate representation of the contrasts between their personalities.
** ''Trigun'' also has the contrast between Vash and cold-blooded [[TheDragon Legato]], who's [[YouGottaHaveBlueHair gotta have blue hair]].
** Vash vs. Knives is a more complex case: Knives is the brainy and coldly rational part of the "duo" but he's also incredibly violent and psychologically unstable. While Vash is a passionate and dynamic character, Knives is prone to feeling lonely and depressed and tends to hang around doing nothing. Moreover, Knives's grand theories actually hide his crazy irrationality, while Vash is able to think with a cold head so as not to take personally all the shit he takes from humans. Manga Knives is often associated with blue and aqua colors, but also with darker reds than his brother. Also note that during their fight at the end of the anime, Vash's vortex is blue and Knives's is red.
* [[GaoGaiGar EnRyu and HyoRyu]], red and blue. Later, they get taken after by yellow [=RaiRyu=] and green [=FuuRyu=], respectively. And then again by light pink [=KouRyu=] and dark purple [=AnRyu=]. They even represent elements - [= EnRyu's fire, RaiRyu's lightning and KouRyu's light for the Red Oni side, and HyoRyu's ice, FuuRyu's wind and AnRyu=]'s darkness for the Blue Oni side. And it's interesting to note that when the first two pairs switch FusionDance partners, they switch across RedOniBlueOni boundaries: [=EnRyu=] combining with [=FuuRyu=], [=HyoRyu=] with [=RaiRyu=].
** {{GaoGaiGar}} himself and King J-Der. Twist: [=GaoGaiGar=]'s G-Stone is ''green'', while J's J-Jewel is ''red''.
* Given a slight twist in ''{{Utawarerumono}}''. The "blue oni" [[spoiler: who is the protagonist in "oni" form]] is literally blue, though the "red oni" is actually mostly black. Also, [[spoiler:[[StarfishCharacter the two turn out to be two halves of a god]], which merge before going into hibernation at the end]].
** Perhaps a better representation in ''{{Utawarerumono}}'' is [[spoiler:Hien and Hauenkua standing side by side as they betray their lord Kuuya, calm and collected Hien in a blue mecha, while borderline insane due to bloodlust Hauenkua sits in a red mecha]]
* Mion of ''HigurashiNoNakuKoroNi'' has a tattoo of a blue oni, prominently featured in the opening. However, she's far more like the red oni in terms of personality. [[spoiler:Then again, the tattoo isn't "hers" to begin with, thanks to an unfortunate TwinSwitch in which ''Shion'' was supposed to get it. As a result, Mion is supposed to act ''Red'' as part of the ''older'' sibling role she's forced to play, while her sister Shion acts ''Blue'' as part of the ''younger'' sibling's role.]]
**Also, in episode 20 of HigurashiNoNakuKoroNiKai, [[spoiler:Hanyuu]] says "If [[spoiler:Keiichi]] is a flame that burns red, then [[spoiler:Rena]] is a quiet, blue flame!"
* ''ChronoCrusade'' reverses the color-coding: Rosette is HotBlooded, brash, energetic and reckless, but wears a blue nun uniform. Chrono, who serves as her [[TheLancer lancer]], is calm, sensitive, and the voice of reason, but wears a striking red coat. However, Chrono himself does have a dangerous temper which flares up at times.
* In the movie ''Tokyo Godfathers'', homeless {{Transvestite}} Hana uses the story of the red and blue oni to illustrate a point to tomboyish runaway Miyuki; in it, Hana explicitly compares [[strike:himself]] herself to the blue oni and the gruff but good-hearted Gin to the red oni.
* Miriya/Max from ''SuperDimensionFortressMacross''. Or the updated version Klan/Michael from Macross Frontier. In both they pilot appropriately color-coded mecha. Although rather than being rivals, they end up love interests, but hey what's the difference?
* Guts and Griffith from ''{{Berserk}}'', with Guts being the violent, determined and impulsive Red Oni to Griffith's cool, calculating and exceedingly ruthless Blue Oni, the ruthlessness even more pronounced when Griffith [[FaceHeelTurn goes bad]]. And Guts, in keeping with the Red Oni, swears unholy vengeance upon Griffith after the horrible betrayal that wipes out the rest of his {{Nakama}} and ends the anime.
** Lampshaded in BerserkAbridged, with Zodd comparing the two with Naruto and Sasuke, though Griffith notes that Guts is way more {{Emo}} than he is.
* {{Pokemon}}: The American release of the first two games, Red and Blue, sort of mirrors the trope. Also, from the anime, we have Ash, the {{Idiot Hero}}, as the perfect example of the Red Oni, while Gary, TheRival, definitely qualifies as the Blue Oni. Paul, Ash's new [[TheRival rival]], seems to have taken over the Blue Oni role, mixed with {{Jerkass}}.
** ''Pokemon Adventures'' features the heroic trainer Red and his rival, Oak's nephew Blue. In the Japanese original, ''Pokemon Special'', however, this was not the case, as Red's rival was Green, while Blue was the female trainer that the English-language version called Green.
* Kamina and Simon of ''TengenToppaGurrenLagann -- blue-shirted and blue-eyed Simon is the comparitively rational one of the two, while red-caped and red-eyed Kamina is...well, ''[[IdiotHero Ka]][[HotBlooded mi]][[{{Determinator}} na]].''
* In ''GundamSEEDAstray'', Lowe Guele (loud, dramatic, impulsive) pilots the Astray Red Frame, and Gai Murakumo (cool, intelligent, professional) pilots the Blue Frame.
* In ''PrinceOfTennis'', Kaoru Kaidoh (skittish, kinda naïve, aloof) and Takeshi Momoshiro (cheerful, a bottomless pit, carefree) might not dress in red and blue, but otherwise they fit the trope to a T. And yes, they play doubles.
** In Hyoutei we have the flighty and loud redhead Gakuto Mukahi and his doubles partner, the suave Yuushi Oshitari (who has blue hair).
* OnePiece has two giants, Dory and Brogy, respectively titled "The Red Ogre" and "The Blue Ogre" on their wanted posters.
* In ''RealBoutHighSchool'', Ryoko has red hair and usually wears her (red) school uniform, while LadyOfWar / TheOjou HeirToTheDojo Azumi Kiribayashi has blue hair and wears blue. On the other hand, Ryoko's central rivalry is with HotBlooded Shizuma Kusanagi, who has a knack for PlayingWithFire and has got a slight red tint to his ''skin''.
* In ''MagicalGirlLyricalNanoha'', the passionate, pink-auraed Nanoha, with her philosophy of [[DefeatMeansFriendship befriending people]] with "[[CatchPhrase Maximum Power]]", is a red oni. Meanwhile, TheStoic, blue-auraed Chrono, who frequently bemoans Nanoha's tendency to use a lot more power than necessary, is a blue oni. The two were even enemies ([[FoeYay and eventually lovers]]) in the [[WhatCouldHaveBeen original]] ''Nanoha'' [[TheAnimeOfTheGame mini-scenario]] of ''TriangleHeart3SweetSongsForever''.
** The second season changes things up by introducing Vita, a tiny girl clad in red that carries around a massive hammer with a hair-trigger temper. Throughout the second and third seasons, she is the Red Oni and Nanoha, who by this time has become much more level headed and calculating, is the Blue Oni among the Wolkenritter.
** And reversed in the case of [[LesYay Subaru and Teana]]. The former's a blue-auraed, blue-haired, HotBlooded GenkiGirl of a red oni. The latter, especially after her RageAgainstTheMentor, is a red-auraed, red-haired, hyper-competent SmartGuy of a blue oni.
* A ''{{Highlander}}'' anime movie called ''Highlander: The Search For Vengeance'' features a strong Red vs Blue rivalry between its protagonist and antagonist. [[RoaringRampageOfRevenge Colin]] is a red with a two thousand year old grudge against the Roman general who slaughtered his people and wife, the blue [[KnightTemplar Marcus]] cares only for bringing "civilization" and order to the world.
* If you look closely, the ''SuzumiyaHaruhi'' series contains a very subtle subversion. At first glance, it may seem as though Yuki ([[TheQuietOne quiet]], [[TheSpock rational]] and [[TheStoic unemotional]]) is the Blue Oni to Ryoko's (cheerful, pleasant, compassionate and somewhat [[spoiler:AxCrazy]]) Red, but actually it's reversed. Over the course of the series, it's revealed that beneath Yuki's expressionless face exists a complex inner world which comes boiling to the surface in the fourth book/second season, while Ryoko is actually a ruthless and emotionally vacant StepfordSmiler whose [[spoiler:foiled attempt on Kyon's life]] was actually a calculated act designed to prompt a reaction from Haruhi.
**Haruhi and Kyon themselves could count as well:Haruhi is a [[HotBlooded passionate]] GenkiGirl, while Kyon is the calm voice of reason and DeadpanSnarker.
* The two ghosts (or whatever they are) in ''TheTowerOfDruaga'', although it's not immediately obvious for two reasons: one, the red girl doesn't show up until episode 8, and it's not the girls themselves that demonstrate the appropriate personality, but rather the person to whom they appear. The blue girl shows herself to [[AloofBigBrother Neeba]], while the red one appears to Jil.
* Noa Izumi and Kanuka Clancy from ''{{Patlabor}}''. One is a slobbish redhead without a college degree who constantly rushes into trouble; the other is a super-professional MIT graduate with glossy black hair (that looks blue) who never lets any situation get to her.
* ''DragonQuest: [[DaiNoDaibouken Dai's Great Adventure]]'' has the clashes between super-HotBlooded [[{{Tsundere}} Maam]] and borderline cowardly Pop. They're respectively dressed in red and pink and in green. Maam and TheStoic Hyunkel form and even bigger contrast, but they get along well while a large amount of screentime is devoted to [[{{SlapSlapKiss}} the conflict between Pop and his "badass goddess of luck"]]. Also notice that Maam is a martial arts specialist and Pop a mage. Avan and Hadler are another interesting case, with Avan as the silly, warm-hearted and spontaneous red oni (he's [[YouGottaHaveBlueHair gotta have blue hair]], but he's dressed in red]] and Hadler as the stubborn and fiery but cold-hearted and stoic green-skinned warrior. Pop and Hadler become increasingly like their counterparts -the former through ThePowerOfFriendship and the latter through the magic of FoeYay.
* ''DNAngel'' has Daisuke Niwa as red and Satoshi Hiwatari as blue, very obvious in their theme colours. Dark and Krad are rather associated with black and white, though they may also be seen as the grown-up and cynical equivalents of their hosts.
* ''CodeGeass'' has scenes where Lelouch and Suzaku are shaded in red and blue respectively, though it counts as a subversion: Lelouch is the cold, tactical one and Suzaku is brash and reckless... but in the end, both can be hotblooded and irrational under pressure.
* Priss Asagiri and Sylia Stingray in ''BubblegumCrisis''.
* The Snow Queen of the anime named after her has a red imp and blue imp as bumbling servants. It's based on a Hans Christian Anderson fairy tale.
* Sakuragi and Rukawa from ''SlamDunk''. Heck, Sakuragi even has red hair.
* In ''{{Mai-HiME}}'', Mai Tokiha is the Red Oni (emotional, passionate, concerned with people), and Natsuki Kuga is the Blue Oni (aloof, mysterious, and concerned with goals). They even have hair colors to match (Mai's is [[RedHeadedHero reddish-orange]], and Natsuki's is [[YouGottaHaveBlueHair bluish-violet]]).
** Mirrored by Arika (red) and Nina (blue) in ''{{Mai-Otome}}''.
* Reversed in {{Kurohime}} - The Fire Elemental is a PaleSkinnedBrunette {{Ojou}} while the Ice Elemental is a pair of hyperactive DarkSkinnedRedHead(s).
* Ame-warashi and Zashiki-warashi, the fairies of ''{{xxxHolic}}''. Ame-warashi has red hair and is brash, rude, and aggressive, while the blue-haired Zashiki-warashi is the shy, quiet, kind one.
* They aren't quite colour coded, but Tamaki and Kyouya of OuranHighSchoolHostClub seem to embody this trope rather well with cool-headed, intellectual {{Chessmaster}} Kyouya balancing up exhuberant, people-focused WhitePrince Tamaki.
* One color may be off, but [[KeroroGunsou Keroro (green) and Giroro (red)]] not only exemplify this trope, they even drag out the trope namer and elaborate on it in one episode.
* ''Shaman King'' loves this. Firstly, there are several instances where the show uses an overlay of two characters, one in red and one in blue - Yoh, the calm, cheerful protagonist, is always the blue character. Also, Amidamaru, Yoh's spirit partner, condenses into a blue spirit flame in battle, which means that Yoh's various oversouls are all blue as well. The major baddies he winds up fighting (Ren at first, then later Hao) have spirits who manifest themselves in red. Finally, there are Zenki and Kouki, two genuine oni who are actually red and blue.
* In ''FushigiYuugi'', friends-turned-enemies Miaka and Yui. Miaka, who is impulsive and passionate, becomes priestess for the god Suzaku, whose element is fire. The more coolheaded Yui becomes priestess for the god Seiryuu, whose element is water.
** A friendly version is done among the male characters: VitriolicBestBuds Tasuki and Tamahome, and later Tasuki and Chichiri.
*** The amusing part is that this is a pun on the symbol on Tamahome's forehead. Go ahead and guess what it is.
* Alucard and Anderson from the ''{{Hellsing}} Ultimate'' OVA. Partially subverted - they both have a [[ChurchMilitant cause]], but both are also [[BloodKnight fighting for the fun of it]].
* In ''DGrayMan'', Allen is warm-hearted and passionate with a case of ChronicHeroSyndrome, whereas Kanda is cynical, aloof and [[DeadpanSnarker prone to making snide remarks]]. Possibly a subversion since WordOfGod says Kanda is the dumber of the two.
** A better example is red-haired Lavi and Kanda - they even have complimentary weapons ([[{{S-CRY-ed}} smash through! slice through!]])
* ''SoulEater'' has this in the form of Black Star and Tsubaki. Black Star is a classic IdiotHero and a complete show-off, while Tsubaki is [[YamatoNadeshiko calm, mature and patient]].
* Jin and Jo from ''InnocentVenus''. Jin is the smooth talker and nice guy [[spoiler: at first]]; Jo is the [[TheStoic intimidating stoic]]. [[ColourCodedForYourConvenience Appropriately]], Jin has [[WhiteHairedPrettyBoy white hair]] and pilots a white mecha, and Jo has dark hair and pilots a black mecha. [[spoiler: Subverted in that Jin really was the villain all along and Jo is the true hero of the series.]]
* In AxisPowersHetalia, Red Oni Alfred/America is cheerful, idealistic, brash, if a little too much; whereas Blue Oni England is his cynical, grouchy, critical, sometimes underhanded, longtime 'frenemy'.
**There's also Red Oni Gilbert/Prussia, an albino who is HotBlooded and CrazyAwesome in the extreme, juxtapositioned with his brother Blue Oni Ludwig/Germany, who is an aloof PerpetualFrowner and DrillSergeantNasty. Also, in what may be a possible LampshadeHanging, Prussia and Germany have red and blue eyes respectively.
* {{Azumanga Daioh}}'s Red Oni homeroom and English teacher Yukari, who is goofy, carefree, fun-loving, and irrational, and wears bright red and yellow clothes, contrasting Blue Oni P.E. teacher Nyamo, who is cautious, caring, responsible, thoughtful, and wears darker blue clothes. Red Oni Tomo and Blue Oni Yomi also fit the trope.
* [[CainAndAbel Rin and Yukio]] from ''AoNoExorcist''. They may be [[HalfIdenticalTwins twins]] but they're completely different: Yukio is a prodigy exorcist-doctor while Rin is the HotBlooded [[AntiAntiChrist son of Satan]].
* IceRevolution: HotBlooded tomboy (her ''coach'' thought she was a boy for a while) {{Idiot Hero}}ine ex-karate prodigy-turned ''figure skater'' Masaki and [[TheRival her rival]] Saaya, a DefrostingIceQueen with (naturally) [[FreudianExcuse a tragic past]].
* CowboyBebop has protagonist Spike, who is dangerously cold in combat but is an easy going, well meaning, impulsive guy outside of it versus EvilCounterpart [[MeaningfulName Vicious]], an utterly ruthless, nihlistic {{Darwinist}} and NietzscheWannabe who seems completely emotionless until he breaks out the SlasherSmile.
** Also, Spike's first partner on the Bebop is Jet, who is a LawfulGood ex-cop who reads 18th century literature, tends bonsai, loves jazz and frequently encourages Spike to use his head more.
** There's also [[FieryRedhead red-haired]] IdiotSavant Edward and [[YouGottaHaveBlueHair indigo-haired]] [[ConMan con woman]] Faye.
* Tenchi Muyo has the very obvious example of sex-crazed, alcoholic, sailor-mouthed Ryoko and her traditionally-minded, honor-driven counterpart, Ayeka.
* Joe and Ken of ''ScienceNinjaTeamGatchaman'', respectively.
* In ''WolfsRain'', [[HotBlooded Kiba's]] relationships with both TheLancer Tsume and [[spoiler: [[StartOfDarkness eventual]] BigBad]] Darcia reflect this dynamic.
*In ''SorcererHunters'', the relationship between the brash and thoughtless [[IdiotHero Carrot]] and his suave older brother Marron is a good example.
* {{Paprika}} and Dr. Chiba [[spoiler: who are the same person]].
*Fai and Kurogane from Tsubasa Reservoir Chronicles, especially through the first arc. They're almost completely colour coded (eyes/clothes even skin colour and hair to an extent) until their positions start to change and Fai starts to crack.
*There's also Natsu and Grey from Fairy Tail, who even have themed powers/auras.
[[/folder]]

[[folder:CollectibleCardGame]]
* MagicTheGathering: Red magic and Blue magic. Red magic, mages, and creatures are all about passion and defiance. Blue magic tends to be big on thought and planning. Also, [[http://ww2.wizards.com/gatherer/CardDetails.aspx?name=Incinerate fire magic]] tends to be red, while [[http://ww2.wizards.com/gatherer/CardDetails.aspx?name=Flood water magic]] tends to be blue.
[[/folder]]

[[folder:ComicBooks]]
* Wolverine (RedOni) and Cyclops (BlueOni) - Wolverine's color may be yellow, but he's easily the RedOni of the team.
* Cutter and Rayek from ''ElfQuest''.
** Eh? who is which? Cutter and Skywise would suit this trope much better, if they weren't soul brothers rather than rivals.
** For that matter, Two-Edge and Winnowill.
* During the DorkAge when {{Superman}} was an energy being, he was briefly split into two separate characters, the calm and rational Superman-Blue, and the hotheaded Superman-Red.
** Or at least this was the writers' intent. In practice, since Superman is usually a pretty calm and rational guy, the blue Supes basically inherited his entire personality, while red Supes just came off as Superman's immature idiot cousin.
* [[GreenLantern Red Lanterns]] are reckless, insane and fueled by rage. Blue Lanterns are tempered, rational and powered by hope.
* Red-wearing {{Deadpool}} is a [[{{Cloudcuckoolander}} completely]] [[CrazyAwesome insane]] variant of BoisterousBruiser, while blue-toned Cable is a calm cyborg CrystalDragonJesus determined to stop the BadFuture from coming to pass.
* Saxon and Kenzie from ''MouseGuard''--even their cloaks match.
* Hawk and Dove of DC Comics are an embodiment of this trope.
* You could make a good argument for {{Batman}} (the cool, calculating Blue Oni) and Robin (the more impulsive Red Oni).
* [[BountyHunter Gen]] and [[GentlemanThief Kitsune]] to [[UsagiYojimbo Usagi]] and [[LadyOfWar Tomoe]].
** Tomoe and [[CompleteMonster Noriko]].
** Usagi and [[TheRival Kenichi]]. In both cases this is amplified by their character designs: Tomoe and Usagi are round and "chubby" while Noriko and Kenichi are lean and angular.
[[/folder]]

[[folder:{{Film}}]]
* ''AbbottAndCostello''.
* [[LordOfTheRings Gimli and Legolas]] (film characterization).
* In the ''{{Hellboy}}'' series, the title character (sloppy hot-tempered demon dating a human flamethrower) and Abe Sapien (studious, slightly prissy gillman) are actually addressed as "Red" and "Blue" respectively; although this is due to, y'know, their actual skin color, the association still fits.
** From ''Hellboy II'', one could argue that Liz is a passionate Red Oni to elf Princess Nuada's polite Blue Oni, though there's not much deliberate contrast made between them.
* The Sith and the Jedi from the ''StarWars'' series fits this trope to a T. The Sith wield red lightsabers and are defined by their passions and their ambitions. While the Jedi typically wield blue or green lightsabers and are presented as more intellectual and steeped in tradition.
* In the movie version of ''LA Confidential'' Edmund Exley is a near-perfect example of a blue oni (and nearly always dresses in a blue suit to boot), while Bud White is very much a red oni (complete with brown/maroon suit).
* In the Will Ferrell movie ''Blades of Glory'' has Chazz Michael Michaels, the improvisational, womanizing idiot Red Oni, and Jimmy Macelroy, the technical, thoughtful man-child Blue Oni. This is even reflected in their "Fire and Ice" costume.
* From ''{{Watchmen}}'', Rorschach/The Comedian/Ozymandias to Dr. Manhattan. Actually, [[strike:anybody]] ''everybody'' is a Red Oni compared to Dr. Manhattan.
** Literally as well as figuratively.
* Every DieHard movie has one or more elements of this. John Mc Clain, the hot headed runner and gunner always goes up against a calculating intellectual BigBad. The first two movies also have a subplot involving Mc Clain's "Red Oni" tactics budging up against the "Blue Oni" by-the-book style of the authority.
* The Henke and Genji clans in ''Sukiyaki Western Django''.
* [[Film.XMen The X-men movies]] had the rivalry between Pyro and Iceman.
* ''{{Underworld}}'' 'verse has raging werewolves versus cold, calculating vampires.
* ''HardCoreLogo'' has the intense, impulsive Joe Dick and the quieter, more calculating, ambitious Billy Tallent.
[[/folder]]

[[folder:Theater]]

* [[WaitingForGodot Vladimir And Estragon]].
* And along the same lines as the above example, [[RosencrantzAndGuildensternAreDead Rosencrantz (red) and Guildenstern (blue)]]
[[/folder]]

[[folder:Literature]]

* In Camus' ''TheStranger'', the borderline-apathetic narrator Meursault is contrasted with the violent, passionate Raymond.
*In ''HarryPotter'', the Marauders' group has two sets. James Potter and Sirius Black, represented by Red, are the dark-haired, rash, prankish HotBlooded. Remus Lupin and Peter Pettigrew are calmer, quieter and more collected than them, having blue traits.
** Wizards (dangerous fantasy) and Muggles (relatively safe reality)
** James and Snape
** [[CloudCuckooLander Luna]] and [[InsufferableGenius Hermione]]
** Ron and Harry
*** Harry and Draco
** Griffindors (hotblooded) and Ravenclaws (intellectual)
*** Hufflepuffs (just happy to be here) and Slytherins (ruthlessly ambitious)
** Trelawney and Macgonagal
*** Macgonagal and Umbridge
** Dumbeldore and Voldemort, and to a relatively (he was a WellIntentionedExtremest, initially) lesser extent Grindelwald
* The BigBadDiumvirate of TheThrawnTrilogy consists of the blue Grand Admiral Thrawn and the red Jedi Master Joruus C'baoth. Thrawn is calculating, AffablyEvil, a planner of {{XanatosGambit}}s, appreciates art, respects his men and his CommanderContrarian, is ''extremely'' pragmatic, and has a temper, but overall is ALighterShadeOfGrey compared to, well, any of the Empire's previous leaders. Also, he has blue skin. Joruus C'baoth is domineering, believes himself to always be entirely in the right, treats non Force-Sensitives like puppets, calls the Empire ''his'' Empire, flies into a violent rage at random, constantly rejects any authority but himself, and is insane. Joruus fell to the Dark Side long ago, and the Dark Side is often represented with red. The two are often at odds, and Thrawn reliably comes off looking better.
** In OutboundFlight, the two highest-ranking people on the Trade Federation taskforce sent by Darth Sidious to destroy Outbound Flight are Kinsman Doriana and Viceroy Siv Kav. Kav is Red - he's impatient, he tries to attack Commander Thrawn's little picket force right away, he resists and blusters when Thrawn captures the two, he never learns to pronounce Thrawn's full name properly and continuously underestimates the commander, and he gets killed when he tries to kill Thrawn. Doriana is Blue and a foil, and not only does he live, he [[StartOfDarkness plants the seeds]] to Thrawn's joining the Empire.
** It's easy to tell that Timothy Zahn likes playing the calculating type off the irrational type, and the calculating type tends to win.
* [[TheLordOfTheRings Boromir and Aragorn]]
[[/folder]]

[[folder:LiveActionTV]]
* ''KamenRider'' has at least a few examples:
** ''KamenRiderRyuki'' has two main heroes: Kido Shinji (Ryuki), who is [[DumbIsGood impulsive and idealistic]], and Akiyama Ren (Knight), who is [[TheStoic stoic]], [[{{Badass}} cool]] and sometimes dangerously close to JumpingOffTheSlipperySlope. Ryuki's armour is red; Knight's armour is normally black, but later in the series he acquires a powerup that turns him blue so that [[ColorCodedForYourConvenience the colours fit the trope]].
*** Western adaptation ''KamenRiderDragonKnight'' also qualifies, though Kit Taylor (Dragon Knight) isn't as HotBlooded or impusive as most Red Oni; he really only looks a little that way when compared to Len (Wing Knight).
** ''KamenRiderKabuto'' has Kagami Arata and Tendou Souji, who fit the trope to some extent, but with some notable exceptions:
*** The blue oni, Tendou, is the main hero.
*** Any victories that Kagami achieves are won at length and through actual effort, not handed to him for free by virtue of DumbIsGood.
*** [[spoiler:The colours of their suits are reversed: Kabuto (Tendou) is red and Gatack (Kagami) is blue.]]
** ''{{Kamen Rider Den-O}}'' has Momotaros, the red oni looking one, who loves the thrill of a good fight. Then there's Urataros, the blue one, who keeps cool at all times and prefers to use deception to get out of sticky situations and score with the chicks.
* Although Justin and Alex, from ''WizardsOfWaverlyPlace'', are both sarcastic and, to an extent, [[DeadpanSnarker deadpan snarkers]], they have really different personalities. While Alex is witty, prankish and lazy, never taking anything seriously (represented by red), her older brother, Justin, is responsible, much more mature, studious and collected (represented by blue).
* ''TokusouSentaiDekaranger'' has Akaza Banban, the Red Ranger/Oni, and Tomasu Houji, the Blue Ranger/Oni. The American version, ''PowerRangersSPD'', does the same with Jack Landors and Sky Tate, although Jack does not embody DumbIsGood to the same extent as Banban.
** Many other ''SuperSentai'' series have the [[TheHero Red Ranger]] as a Red Oni, and several have the Blue Ranger as something of a Blue Oni. Apart from ''Dekaranger'', few have their relationship as a major theme, though.
** Gai and Ryuu of ''ChoujinSentaiJetman'', though their colors are reversed: Ryuu (TheHero) is the Blue Oni but wears red, and Gai (TheLancer) is the Red Oni but wears black.
** Speaking of ''PowerRangers'', the original series (''MightyMorphinPowerRangers'') fit the trope to an extent - the Red Ranger was the confident, extremely physical leader of the band while the Blue Ranger was the intellectual of the bunch. The other three members (the Pink/Girl, Yellow/Asian and Black/Afro-American Rangers) probably fall under [[UnfortunateImplications Unfortunate Implications]]....
* Jack O'Neill and Dr Daniel Jackson from ''StargateSG1'' could fit into this trope as many of the earlier episodes conflict came from O'Neill's emotional pragmatism conflicting with Daniels intellectual desire to study and understand various things.
** Ronon and Teal'c have this kind of relationship in the StargateAtlantis episode "Midway". Ronon being the aggressive and wild Red Oni and Teal'c being the calm and cultured Blue Oni. And both being TheBigGuy of their respective show.
* Malcolm Reynolds and Simon Tam of {{Firefly}} fit this so perfectly, it's kinda scary. Hell, the corresponding colors are even in the opening titles.
** [[JossWhedon Joss]] has fun playing with this trope: at first, it seems as though Simon will be the villainous Blue Oni to Mal's Heroic Red, but this is not the case; Simon actually turns out to be at least as heroic as Mal, perhaps even more so.
** To an extent, this also applies to Mal and Shepherd Book. Although Book has a somewhat rough, earthy nature akin to a red oni, he is also a very intellectual, spiritual, and cultured individual. Besides that, there's his heavily hinted past with the Alliance, which is about as blue an organization as you can find.
** River also occasionally plays Red Oni to Simon's blue, and Zoe plays Blue to Mal's Red.
** While Jayne embodies the physical and mental qualities of Red and Simon of Blue, they are vice versa emotionally.
*** They are? Isn't Jayne more "hot-blooded" and Simon more "intellectual, proud, traditional, and cultured?"
* This trope fits very well with {{Lost}}. Jack - though a doctor, which is very blue in nature - is a very passionate, people-oriented, and frequently rebellious leader. Locke, on the other hand, is more preoccupied with spiritual matters, such as destiny and purpose, as well as more learned in a greater variety of fields. Interestingly enough, though Locke has also frequently shown signs of the blue oni villain through his coldness towards others, Jack's ruthlessness is far more potent, as depicted when [[spoiler: Locke cannot bring himself to shoot Jack in order to stop him talking to the freighter people, but Jack is fully willing to shoot Locke when the two next encounter each other.]]
** Though, when it comes to classic Evil Blue Oni, it's pretty hard to match [[TheChessmaster Ben]].
*** And Sawyer is both ''in one person''!
* Peter and Nathan Petrelli from ''{{Heroes}}'' Nathan takes the role of the AloofBigBrother while Peter is the younger, emotional, and unfortunately for many an IdiotHero. Also, Peter and Sylar, according to how their powers work(Peter's is empathy, Sylar's is intuitive aptitude). However in Season 3, [[spoiler:Peter absorbs Sylar's ability, making him have the ''hunger'', and Sylar has had Peter's ability all along]]. Also deconstructed in a future episode, where Peter summons fire while Sylar summons ice. It makes even more sense since [[spoiler:Peter and Sylar are revealed to be brothers.]]
** Except, [[spoiler: it's later revealed that was [[AssPull just a lie]] and they are in fact not brothers]].
** Also if you compare the heroes with their future selves, who are all apparently ''{{Badass}}''. [[spoiler:It's inverted in the case of ''Sylar'', where he moved into Claire's home, calls himself Gabriel(his real name) and is much nicer than his present self. He even has a ''son'', named ''Noah''.]]
** Inverted in the case of the siblings [[spoiler:Meredith and Flint]]. Meredith has the red fire, but she is much more calmer and level-headed than her younger brother, who's about as bright as a flea but has the blue fire. However, since Meredith is on the side of good, she possesses a genuine warm (pardon the joke) and caring personality for her family while her brother is ruthless and even killed a woman with his powers.
* [[TheSpock Spock]] (fittingly costumed in blue) is a classic blue oni on StarTrekTheOriginalSeries; on the occasions when they're not all chumming it up as a PowerTrio, [[TheKirk Kirk]] and [[TheMcCoy McCoy]] each often serve as red oni to his blue, depending on who's playing off whom at the moment. Red and blue aren't specifically used as contrast colors for them--[=McCoy=] wears blue as well--but their red human blood and his "cooler"-colored green Vulcan blood are often contrasted.
** Also, the show buys into this trope in a more general way: science and medical personnel, the knowledge-oriented "brains" of the outfit, wear blue, while operations, security and engineering, the action-oriented "brawn," wear red.
*** WilliamShatner and LeonardNimoy themselves are RedOniBlueOni. While William Shatner...[[{{Understatement}} won't...hesitate]]...[[LargeHam tochewupthescenery]]...and...MAKE HIS PERFORMANCE LARGER THAN...[[TheKhan LIIIIIIIIIIIIFE]], LeonardNimoy focuses on portraying the complexities of a more nuanced character.
* [[ActionMom Sarah]] and [[EmotionlessGirl Cameron]] from ''TheSarahConnorChronicles''.
* ''PrisonBreak'''s protagonists, brothers Lincoln Burrows (red) and Michael Scofield (blue), fill this trope to a T.
* While not on the same shows (or even the same channel), [[DuelingMovies "dueling"]] pastry chefs Buddy (The Cake Boss) and Duff (Ace of Cakes) have opposite personalities: Buddy is extremely HotBlooded while Duff is considerably more relaxed; this extends to their surroundings: Buddy's bakery is a neighborhood institution and is mostly staffed with his family (including his [[CoolBigSis four older sisters]]) while Duff only does specialty cakes and is surrounded by his friends.
* '''Blake's 7''' has two pair of these, one on each side, for the first two seasons: red oni Roj Blake, passionate freedom fighter, frequently reckless, and his {{Lancer}}, blue oni Kerr Avon, coldblooded "what's in it for me?" tech, versus blue oni Servalan, primary power of the evil Republic, and her revenge-obsessed red oni general Travis.
** In season 3, with Blake vanished, Avon ends up stuck with red oni/brash youth Tarrant while fugitive Sevalan doesn't bother to replace the dead Travis.
* A DisneyChannel movie called "Stepsister from the Planet Weird" had this for the two families: the down-to-earth Earthlings were blue while the literally air-headed (they're bubbles) and overly emotional aliens were pink/orange. Naturally, their wedding theme was purple.
* ProfessionalWrestling is chock-full of these. To wit:
** [[NamesToRunAwayFromReallyFast The Brothers of Destruction]], Undertaker (Blue) and Kane (Red).
** [[InNameOnly The Hardy Brothers]], Jeff (impulsive and aerial Red) and Matt (more calculated and ground-based Blue).
** Former WWE Unified Tag Team Champions, [[TheRealWorld Mike "The Miz" Mizanin]] (angry Red) and John Morrison (mellow Blue).
** The Rockers (originally AWA's {{Expies}} of the Rock 'n' Roll Express from the NWA), Marty Janetty (Blue) and Shawn Michaels (Red); notable for the fact that the group originally split after they gradually switched roles over the course of their 5-year tag team career.
*** In the same vein, the current iteration of D-Generation X, with Shawn Michaels back in the Red Oni role and partner/best friend Triple H in the Blue Oni role (it can also be noted that [[DontCallMePaul Hunter]] can switch the colors pretty much on demand now as a story needs him to).
** Classic big-man tag team [[MeaningfulName The Twin Towers]], where the Big Boss Man (prior to his HeelFaceTurn) was the Red Oni and Akeem "The African Dream" (after switching gimmicks from the One Man Gang) was the Blue Oni.
** The Outsiders, Kevin Nash (Blue) and Scott Hall (firmly entrenched in Red terrritory).
** Even Mick Foley (jokey Red) and Al Snow (serious Blue) meet this trope head-on!
** Even the ANNOUNCERS get in on the action!
*** The classic team of Jim Ross (Blue) and Jerry Lawler (Red).
*** Classic ECW's Joey Styles (Red) and Joel Gertner (Blue). OH MY GOD!!
*** Michael Cole (Red) and Tazz (Blue).
**** When Tazz went to the ECW Brand, Cole became the Blue to John "Bradshaw" Layfield's hard-Red.
*** Gorilla Monsoon (Blue) and Jesse Ventura (Red). Gorilla was firmly Red, however, when teamed with Bobby "The Brain" Heenan (cold, calculating Blue).
**** On that token, "Rowdy" Roddy Piper lived up to his moniker when he served as Monsoon's replacement Red with Brain.
[[/folder]]

[[folder:VideoGames]]
* Ada and Leon from ''{{Resident Evil}}'' fit this trope well. Ada is known for wearing the color red, where argueably Leon's trademark color would be blue as in his RPD uniform. The two are on opposite sides of the spectrum and often clash over similar or different goals. Also an example of {{Opposites attract}}.
* Ken and Ryu from ''StreetFighter'' are an arguable case. (Ken is brash, cocky, innovative and his favorite move is the uppercut, best performed at close range, Ryu is philosophical, traditional, and prefers using the fireball from a distance. This does not apply to all of their [[RyuAndKen clones]].)
* Sakura Kasugano (blue) and Karin Kanzuki (red) from StreetFighterAlphaThree.
* In the third ''Tenchu'' game, the [[EvilOverlord evil wizard]] Tenrai employs both blue and red demons as foot soldiers. They're not given much personality, but if you're spotted and get drawn into a fight, the red ones will simply keep fighting until killed, while the blue ones will try an explosive [[TakingYouWithMe kamikaze attack]] once their health is low.
* In the second ''{{Onimusha}}'' game, the always-drinking, eating, and lecherous Ekei can pass for a red oni (and dresses all in yellows and reds), while the serious, book loving, thoughtful Magoichi is a blue oni (complete with blue clothes).
* In the ''ViewtifulJoe'' anime, Joe wears a red costume in hero form while Junior wears a blue costume in hero form. Joe is the strong, energetic, reckless one, while Junior is shaping up the be TheSmartGuy. The color-coding is reversed in their normal forms, however.
* ''SuikodenII'' has lovable henchmen Seed and Culgan who wear red and blue respectively and pretty much embody the concept.
** Not to mention the ''main characters'' of the game, Riou and Jowy.
* Perhaps played with or perhaps just a coincidence, but in ''PhoenixWrightAceAttorney'', the highly emotional hero who gets by largely on luck always wears blue, whereas his [[TheRival Rival]], the stoic, intellectual, supremely controlled Miles Edgeworth wears red.
* Most ''FireEmblem'' games give you two near-identical horse-mounted knights at the beginning of the game: One will wear red armor, have an outgoing/reckless personality, and have more Defense and Attack power, while the other wears green, behaves modestly, and specializes in speed and accuracy. It fits the trope better once you remember that the Japanese, like many other cultures, don't fully distinguish between green and blue.
** And then ''Blazing Sword'' goes and inverts it - Sain, ChivalrousPervert, is in green and Kent, his superior in both rank and self-control, is in red.
*** Another inversion in ''Blazing Sword'' occurs with two of the main lords: [[HotBlooded brash]], [[YouGottaHaveBlueHair blue-haired]] Hector and [[TheWisePrince calm, formal]] [[RedHeadedHero red-head]] Eliwood.
* Atsuma and Touya of ''EnchantedArms'' fit the trope almost perfectly: seeing as how the game contains more than a few gaming/character stereotypes, this should be no surprise.
* FinalFantasy examples:
** In ''FinalFantasyX'', Tidus and his father Jecht are both HotBlooded red types who favor the IndyPloy and have impulse control issues, while [[TheStoic Auron]] is a blue. [[spoiler:So is Seymour, the main onscreen villain.]]
** ''Final Fantasy X-2'' has Yuna positioned between red Rikku and blue Paine.
** In ''FinalFantasyVIII'', the protagonist Squall is a blue (and wears black) while RivalTurnedEvil Seifer is a red (and wears white).
*** On a smaller scale the Biggs and Wedge pair in VIII are also a colour coded example of this, Biggs is brash, aggressive and ambitious, Wedge is his cool headed, reserved and long suffering subordinate.
*** On an even smaller scale, in ''FinalFantasyIV'', twins Palom and Porom. Palom uses Black Magic; he's brash and always getting himself into trouble. His twin sister Porom uses White Magic; she's studious, dutiful, and constantly smacking her brother upside the head to get him to behave.
** ''FinalFantasyIX'' has [[ChivalrousPervert Zidane]] and [[WhiteHairedPrettyboy Kuja]], which sort of makes sense when you consider [[spoiler: they're brothers]].
*** It is later subverted: Zidane becomes a lot more responsible and thoughtful, while [[OmnicidalManiac Kuja...]]
*** Even the planets Gaea and Terra are colour-coded according to this convention.
* The TechnicalPacifist blue-armored X and the aggressive red-armored Zero in the ''MegaManX'' games.
** And the aloof blue ice-element DarkActionGirl Leviathan and red fire-element berserker Fefnir in the ''MegaManZero'' games.
** And the blue EmotionlessGirl Pandora and berserk (even moreso than Fefnir) Prometheus in the ''MegaManZX'' series.
** Inversion in ''MegaManBattleNetwork''. Lan and [=MegaMan=] are blue, Chaud and Protoman are red. Chaud's the [[AloofBigBrother Aloof]] [[TheRival Rival]] to Lan's IdiotHero, and while Rock is a lot more savvy and collected than his Operator, Protoman's professionalism and businesslike manner still plays Blue Oni to his PowerOfFriendship philosophies.
* Reversed in ''SonicTheHedgehog''; our titular blue hero is a lot more outgoing and carefree than his red-clad counterpart, Shadow. Of course, there's still the red Knuckles.
* ''DevilMayCry'': 3 has Dante (Red, arrogant, sarcastic, impetuous, good-guy) and Vergil (Blue, sombre, stoic, ruthless, bad-guy); 4 has Dante (ditto) and Nero (Blue, dedicated, also good-guy).
* The ''SuperRobotWars'' series gives us the awesomeness that is the hotblooded Sanger Zonbolt and his [[HeterosexualLifePartners Heterosexual Life Partner]] and intellectual {{foil}} Elzam Braunstein. Each of them is a total badass in a different way, one spouting absurdly cheesy lines but making them pure gold while the other serves as an AloofBigBrother whose theme song trumps all others? Although like some incarnations, the Red Oni Sanger's mechs will more likely have a dominant color of blue, while Blue Oni Elzam always paints his mechs red.
* HotBlooded Ralf Jones (red oni) and TheStoic Clark Still (blue oni) from ''IkariWarriors'' and ''TheKingOfFighters''. Ralf beats enemies down with explosive punches and ''lots'' of [[CallingYourAttacks yelling]], while his partner Clark is much more inclined to break his opponents' bones with grappling moves without breaking a sweat (or saying much of a word).
* Kazuki and Sogetsu from ''SamuraiShodown''. Both are ninja, but the former dresses in red, is hot-tempered, and has fire-based powers; the latter dresses in blue, is far more composed, and has water powers.
* Shows up, oddly, in MassEffect with Urdnot Wrex and Garrus Vakarian, who default to red and blue armor respectively and are a semi-criminal mercenary and a cop. Oddly subverted in that Wrex, while violent and impulsive, is actually fairly stoic and difficult to anger, while Garrus is significantly more hot-tempered and easier to rile.
** Ashley and Kaidan also play more standard Red Oni / Blue Oni roles, albeit with less color-coding; in a dialogue option partway through the game, Commander Shepard says that when s/he wants an answer "from the head," s/he goes to Kaidan, and when s/he wants one "from the heart" s/he goes to Ashley. [[spoiler:Eventually Shepard (and by extension the player) is forced to choose between them.]]
*** Shepard can also join in on this trope thanks to the game's KarmaMeter, though with some slight inversions. Blue-coded paragon Shepard tends to be more personable, while red-negade Shepard is more self-centered and cynical.
* TheChosenOne Sora and [[spoiler:MissedTheCall]] RivalTurnedEvil Riku from ''KingdomHearts'' definitely have this mechanic at work.
** This is especially blatant in ''Chain of Memories'', where Sora and Riku have red- and blue-tinted title artwork.
** [[spoiler:Axel and Saix]] in ''358/2 Days''.
* In ''SilhouetteMirage'', nearly all lifeforms are divided into two categories: the Silhouettes, who represent force, emotion and determination, and the Mirages, who represent intelligence, technology, and cold logic. Oddly, the typical color scheme is reversed: Silhouettes are blue while Mirages are red.
* Played straight in ''GunstarHeroes'' and GunstarSuperHeores, to the point where, in addition to having personalities entirely constructed on this trope, the dual protagonists are ''named'' Red and Blue.
* ''{{Castlevania}}: Curse of Darkness'' has Isaac the Red Oni, who is emotionally-driven, vengeful, passionate and embodies the {{FoeYay}} trope; Hector, your hero, is the Blue Oni. He's told - and tells himself - often to keep his cool and not get all 'riled up' by Isaac's antics, {{if you know what I mean}}, so as not to be overtaken by Dracula's curse. Their [[http://www.vgmuseum.com/mrp/multi/officialart2.htm#cod official wallpapers]] make their Convenient Oni Colour Coding clear, if we didn't catch it the first time.
* ''{{Xenogears}}'': Dominia and Kelvena, members of [[QuirkyMinibossSquad the Elements]], are red and blue, respectively. Dominia is impulsive and vengeful, while Kelvena is calm and reserved. [[ColorCodedForYourConvenience They even wear red and blue]].
** Come on: Xenogears could be almost renamed "Oni meets Christianity (IN SPACE!)": We have Fei, the brash martial Artist, and Elly [[spoiler: technically his substitude mother AND wife since the crash of the Eldridge 10.000 years ago (Freud would have loved this game)]] the more composed officer: Fei's angers are [[SuperpoweredEvilSide a sight to behold]] and Elly is the only one who can calm him [[spoiler: she's probably the only one who's tought enough to wistand the full extant of his anger anyway]], and a flashback shows us that [[spoiler: 500 years ago, during the diabolo's war, and even 40 CENTURIES ago during the Zeboim era]] she was already the blue, calmer part of their couple. Apart Fei and Elly, we have Citan (so blue that sometimes it take time to understand that the man is [[TranquilFury really angry]] ) and the red hot blooded Bart while on the villain side we have Ramsus (who gets reder and reder during the course of the game) and Miang, who is so blue that it even affect her [[ColourCodedForYourConvenience hair]], or the [[PowerTrio trio]] formed by ID, who like Miang is [[ColourCodedForYourConvenience hair coded]], Grahf (middle ground) and [[MagnificentBastard Magnificent Bluestard]] Krelian...
* ''SengokuBasara'' has two examples of this. There's poster boys Sanada Yukimura as the HotBlooded [[PlayingWithFire fire-user]] and GratuitousEnglish spouting [[ShockAndAwe Lightning-wielder]] Date Masamune - Masamune is pretty HotBlooded himself, but still serves as the Blue Oni in comparison to Yukimura. There's also Takeda Shingen, Yukimura's equally Hot Blooded commander and [[AnIcePerson Ice-using]] [[ImplausibleFencingPowers swordsman]] Uesugi Kenshin.
* Not directly used, but possibly referenced in ''Perfect Cherry Blossom'' of the ''{{Touhou}}'' series: In the [[BonusLevelOfHell Extra Stage]] MidBoss battle against Chen, one of Chen's spell cards is named Oni Sign "Blue Oni Red Oni". Half the bullets rush directly at you, while the other half drift around slowly in a somewhat random direction, though there are both red and blue bullets of both types.
** For a more direct representation of the trope, ''Mountain of Faith'''s [[PhysicalGod goddesses]] Kanako and Suwako fit the bill.
** For an even more direct representation of the trope, we have Yuki and Mai, the [[DualBoss stage 4 bosses]] of ''Mystic Square'', one of the old generation games. Yuki is the Red Oni: she's upfront with the protagonist, and she uses fire magic (usually blanketing the whole field). If Mai is defeated first, Yuki will be in a state of [[HotBlooded righteous indignation]] when she [[TurnsRed gets serious]]. Mai is the Blue Oni: She barely says a word before the battle, and she uses cold magic (usually aimed straight at the player). If Yuki is defeated first, Mai will declare that Yuki was dragging her down and now she doesn't have to hold back.
* While ''TheWorldEndsWithYou'''s protagonists are very much a mixture of traits (Neku and Joshua being blue with red spots, Shiki and Beat being red with blue spots), a much neater organization can be found among the Reaper Organization. The best example of [[RedOniBlueOni Red Oni Blue Oni]] is probably Koki Kariya (Blue) and Uzuki Yashiro (Red).
* Heat, the short-tempered, impetuous and [[spoiler:eventually antagonistic]] [[TheLancer lancer]] who transforms into the fire demon Agni and Serph the rational, calm and almost emotionless leader who transforms into ice demon Indra in ''DigitalDevilSaga''.
* Red Oni Sol Badguy and Blue Oni Ky Kiske from ''GuiltyGear''.
* ''{{Blazblue}}'' has Ragna and Jin. Iron Tager is actually nicknamed "The Red Oni" (Translated as "The Red Devil"), but this has to do with his fighting prowess and physical resemblance to one, and he doesn't really fit the archetype.
* ''AdvanceWars: Days of Ruin'' has Tasha/Zadia, a FieryRedHead who is driven by vengeance for her dead brother, and her co-commander Gage/Trak, a TheStoic blue-haired ColdSniper. They're commanders in the same army, and very much foils of each other.
* Obligatory ''TheLegendOfZelda'' reference: Ganondorf, the resident BigBad, is represented by the color red -- the color of Din, Goddess of Power, whose portion of the Triforce he wields. The color of Nayru, Goddess of Wisdom, is blue, and synonymous with her acolyte, the wise, kind, serene Princess Zelda.
**Dont forget in ''Link's Awakening DX'', the Red Clothes boost offense whereas the Blue Clothes boost defence. This is reused in the ''Oracle'' games with the Red/Blue, and Power/Armor rings.
* The ''DeptHeaven'' games just love to reverse this trope.
** ''RivieraThePromisedLand'' has red-themed Ledah with a blue personality and blue-themed Malice with a red personality.
** ''YggdraUnion'' has [[spoiler:twin sisters]] Luciana and Aegina; while Luciana is red and Aegina is blue, Luciana's trademark colors are black and blue and Aegina's is red.
** ''KnightsInTheNightmare'' has Maria, Marietta, Meria, and Melissa. Maria and Marietta have red-and-gold coloring with blue personalities, while Meria and Melissa have blue-and-purple coloring with red personalities.
*** However, the Law and Chaos phases bathe the battlefield in blue and red, respectively. [[color:#0000cc:Uphold the law!]] [[color:#cc0000:Let chaos reign!]]
* The Shaolin (red) and Counter (blue) classes in WindSlayer. Their out-of-game portraits are even ColorCodedForYourConvenience.
* ''{{Okami}}'' has a pair of enemies known as "Red Oni/Ogre" and "Blue Oni/Ogre". They attack with fire and ice, respectively.
* Jyuji Kabane and [[NamesToRunAwayFromReallyFast Rocketbilly Redcadillac]] from ''{{Gungrave}} : Overdose''. One is a hot-tempered, undead blind warrior who constantly makes death threats against those who annoy him and who's fast in attacking his opponents without really thinking of a plan first (and he's DualWielding red gunblades), the other is a kind and somewhat naive rocker ghost with a heart of gold who loves the ladies (and his weapon is a blue electric guitar). TheyFightCrime.
* Reversed in ''ChronoTrigger''. Ice-wielding Marle is outgoing, friendly and impulsive; fire-wielding Lucca is a levelheaded GadgeteerGenius.
* Twin Sisters of the NasuVerse, Aoko and Touko are this. One is chaotic, the other lawful. Touko was originally depicted as having blue hair until the ''{{Kara No Kyoukai}}'' {{OAV}} gave her an AdaptationDyeJob to more resemble her ''twin'' sister. Genetics beats out symbolism these days. Nevertheless, their Mage Titles are "Red" and "Blue." (Don't bring it up, it's a sore subject.)
* Axel and Saix play this as straight as can be in ''KingdomHearts'': 358/2 Days, complete with the hair colors to match.
* What, no mention of ''TalesOfSymphonia''? Lloyd and Genis even match the colors: Lloyd is athletic, aggressive, puts all his focus into physical combat and dresses in all-red. Genis is much more studious, much more willing to play by the rules, much calmer, puts all his focus into magical combat and dresses in all-blue.
** Tales of the Abyss also follows this trope. The main character, Luke, sports firey red waist-length hair and is extremely emotional and aggressive. The party's scholar, Jade, is calm, cool, collected and sports an incredibly sharp wit. He is clad almost totally in blue.
* Reversed in the ''AceAttorney'' series, where the lawyers with the more fiery reddish qualities (Phoenix, Francizka etc.) have a blue motif in their dress, while the more aloof ones (Edgeworth, Godot's visor) have a red motif.
* Featured prominently with the two races added in the first ''WorldOfWarcraft'' expansion. The arrogant and reckless Blood Elves have a notible red color scheme, while the noble Draenei have a blue scheme. They even have red and blue underwear.
* The portable remake of ''{{Persona3}}'' has managed to pull off a fairly rare ''DistaffCounterpart'' version of this by introducing the option to have a female protagonist; the male protagonist is typically a bit reserved and intellectual and is accordingly given blue hair and eyes (and a blue in-game interface); the new female option is quite a bit more outgoing and cheerful and is naturally themed red with her hair and eyes.
* Ky Kiske and Sold Badguy from Guilty Gear
* The ''SuperMarioBrothers''! While originally the Bros. were little more then a PaletteSwap of each other until DivergentCharacterEvolution split them apart. Mario, being the titular hero, wears red and is the all-around happy-go-lucky, kick-assy, everyone(except Bowser)-lovesy guy. Whereas the green-clad Luigi became portrayed as a Cowardly Lion, who is rather introverted and at times even outright ignored by the game's cast. Poor guy.
** Appropriately enough, in ''MarioAndLuigiSuperstarSaga'', after visiting two temples, Mario gets the power of (red) fire and Luigi gets the power of (blue) thunder.
* Subverted in the original ''{{Myst}}'': Achenar is passionate, strong, uncontrollable to the point of insanity, and an excellent hunter while his little brother Sirrus is calm, sophisticated, manipulative, and a brilliant technician. Nonetheless, Achenar is trapped in the Blue Book when you meet him, and Sirrus is trapped in the Red Book.
* ''Ikaruga'' main gameplay mechanic makes use of positive(white/blue) and negative(red/black) energy shots.

[[/folder]]

[[folder: WebComics]]
* ''SluggyFreelance'' has Oasis and Kusari, two gymnastic assassins of mysterious origin with superhuman and probably supernatural powers. Oasis is basically insane as a result of MindControl gone bad, which involved manipulating her emotional states. She is left impulsive and compulsive about the emotional reactions she was ordered to have before her controller was killed, and is often incapable of rational thought. Recently, it's even be discovered that she is pyrokinetic, just adding to her fiery repertoire. Kusari obeys orders unfailingly, possibly also mind-controlled, but is still capable of rational thought and always remains cool. The two look about as identical as they can under their respective outfits considering that Kusari is always masked, but Oasis's most noticeable feature is her fiery red hair, whereas Kusari is always shown in the same bluish-purple outfit. There is [[EpilepticTrees speculation]] that the contrast between the two hides symbolism hinting at their as yet unknown origins.
** Torg and Riff also can be contrasted with Torg as a definite Red and Riff as Blue(ish)
* ''ElGoonishShive'' has Tedd and Susan, sort of. In this case, it's more of a personality difference as Tedd is generally upbeat and unobservant while Susan is a DeadpanSnarker. Other characters lean towards both sides, but generally hover in the middle.
* Krushcor and Beryun from ''TheGodsOfArrKelaan'', they are respectively [[BloodKnight The God of Battles]] and [[TheStrategist the Goddess of War.]]
* ''[[{{Ptitlejmt00a4r}} Fetch Quest: The Saga of the Twelve Artifacts]]'' has [[ActionGirl Saffron]] [[RebelliousPrincess Lachesis]] and her twin Nephilim. No guesses as to [[http://www.fetchquest.com/archive.php?chapterid=7&comicid=6 who's who]].
[[/folder]]

[[folder:WebOriginal]]
* While most of the characters tend towards red oni, ''[[RedVsBlue Red Vs. Blue]]'' has a bit of this going on in the different teams, mostly their leaders. Church, the man in charge of the blue team, is fairly on-the-ball and tries to get things done, and he took over from Butch Flowers, a soft-spoken, thoughtful man whose only flaw seemed to be in thinking that the whole Red Army versus Blue Army conflict was something of a game and strategizing accordingly (in a flashback, when Church reports on Red activity, Flowers refers to them as "Those rascals!" in a no-hard-feelings sort of way). Sarge, leader of the red team, puts exactly no thought into his battle plans beyond how they can be used to kill Grif, but he goes at them with such a fervor that, if he did think about his plans for three seconds straight, he might actually win.
* ''GantzAbridged'' actually calls this trope out in a full-on ShoutOut to the TV Tropes Wiki, with an actual Red Oni alien telling a Green Oni alien that he's supposed to be Blue and asking if they're subverting the trope. The trope is then furthered carried out when the Red Oni decides to immediately resort to smashing things, to which the Green Oni replies, "You WOULD say that."
* [[AwesomeSeries Egoraptor's]] anime parody "girlchan in Paradise" contains two non-human characters, one with blue skin and one with red skin. The blue one, Kodobaru-san-sama, is a cool and collected OldMaster, and the red one, galacticamaru, is a power-mad LargeHam who likes smashing through walls, and happens to be the BigBad.
[[/folder]]

[[folder:WesternAnimation]]
* ''TeenTitans'' has two sets of this. [[BadassNormal Robin]] and [[GenkiGirl Starfire]] are represented by Red and are more brash, stubborn and passionate then the others (Starfire displays this most in the [[Comicbook/TeenTitans comics]] to which the flashback/origin episode "Go" paid tribute). [[GeniusBruiser Cyborg]] and [[DarkMagicalGirl Raven]] are represented by Blue and are more intelligent, analytical, and in Raven's case, cold.
** In the current [[Comicbook/TeenTitans Teen Titans comic]], Red Devil (literally a Red Oni) and the new {{Blue Beetle}} have become a comic relief {{dynamic duo}} that fans have dubbed Beevil. While both characters have similar personalities, Beetle tends to be level headed while Devil is more impulsive.
** Don't forget about Thunder (blue) and Lightning (red) from the 4th episode.
** Slade is definitely the villainous Blue to Robin's heroic Red.
* ''AvatarTheLastAirbender'' has played with the red vs. blue color game quite a bit. Probably the most clear cut case for this in actual characters is the contrast of angry, defiant {{Determinator}} Zuko, who lives and dies with the IndyPloy (although he is by far one of most complex reds), and the DangerouslyGenreSavvy [[TheChessmaster Chessmaster]]/[[TheDragon Dragon]] Azula, who even makes blue fire (which is actually hotter). Some other notable examples of playing with red vs blue include:
** Zuko's DreamSequence, where his [[TheObiWan Uncle Iroh]] is represented by a red dragon and Azula by a blue.
*** Zuko also used a visibly different fighting style [[spoiler:when he was "The Blue Spirit"]].
** Best friends [[RivalTurnedEvil turned enemies]] Avatar Roku and Firelord Sozin both had dragon companions. Roku's was red, Sozin's blue.
*** Also note the foreshadowing, as They are both [[spoiler:Zuko's ancestors, and Sozin left Roku to die under tons of volcanic soot.]]
** [[spoiler:Aang and Zuko are taught a different version of Firebending philosophy and forms at least in part by a red and blue dragon.]]
** Aang is, appropriately enough, a combination of the two. Aang normally can be both foolish and passionate (represented by his normal saffron clothes [[spoiler:and temporary Fire Nation wardrobe change, which he later salvages to make a new set of robes]].) But when in his glowing blue Avatar State, Aang can become frighteningly cold and ruthless, to the point where Aang himself has nightmares about it.
* Although, at first, Stan and Kyle from ''SouthPark'' had similar personalities, later on, they were differenced. Stan was an introvert, calm DeadpanSnarker, while Kyle was an impulsive, bold HotBlooded, especially in Cartman's presence.
** Tweek and Craig fit this trope, as well. The former is hyperactive, paranoic, anxious, who shows his emotions easily, while the latter has a darker personality, being stoic, pragmatic, monotone and ironic.
* Possibly unintentional, but Blitzwing of ''TransformersAnimated'' has a SplitPersonality represented by his three faces. The black face is TheMadHatter, but the red and blue faces are textbook red and blue oni, the blue face cold, calm, and calculating (and uses ice powers), while the red face is brash, impatient, and agressive (and uses a flamethrower).
** Even his alternate modes reflect this; the blue face wanted to choose a fighter jet, maneuverable and good for attacking from a distance, while the red face insisted on an assault tank, heavily armored and bristling with firepower, ideal for being right in the middle of the action. After they'd argued for a bit, the crazy face stepped in and, cackling madly, scanned both; which one he uses depends on which of him is driving.
* Sparx the red monkey and Gibson the blue monkey from ''SuperRobotMonkeyTeamHyperForceGo!''.
* In ''JusticeLeague'', Hawk and Dove, who are also [[YinYangSiblings brothers]] [[spoiler: then one brother and a girl, then two girls, according to the DC Encyclopedia]].
* In ''XiaolinShowdown'' good examples on the villain side are Jack Spicer(red) and Chase Young (blue).
* Leonardo (blue) and Raphael (red) in ''TeenageMutantNinjaTurtles''. Reversal in that Leo is the leader of the team (aside from [[{{OldMaster}} Splinter]]). Raph does the BloodKnight bit when he takes the guise of [[spoiler: Nightwatcher]] in the CGI movie.
** In fact, they pretty much summed up the trope in four words with this exchange from the first episode of the [[WesternAnimation/TeenageMutantNinjaTurtles2003 '03 series]]:
--->'''Raph:''' Teacher's pet!
--->'''Leo:''' Ninja dropout!
* Inverted with Pablo and Tyrone of ''TheBackyardigans'': Pablo's blue, HotHeaded, and panicked a lot in season 1, placing him as the Red Oni. Orange-furred Tyrone, on the other hand, is calmer and more level-headed, which are true aspects of a Blue Oni.
* In in the cartoons series for Disney's ''Hercules'', Ares the God of war and Athena the Goddess of wisdom who are siblings and rivals were perfect representations of this trope.
* ''{{Disney/Aladdin}}'' the AnimatedSeries: [[TheHero Aladdin]]: Red/purple and white, uses his own strength, lives with a mess of friends, has a monkey sidekick, versus [[DracoInLeatherPants Mozenrath]]: Dark blue and black, uses magic, lives pretty much alone in a ghost city, has an eel sidekick.
*In {{Taz-Mania}} the Taz/Dingo shorts, Taz plays the role of the HotBlooded red oni while Digeri Dingo plays the role of the cool and cunning blue oni. Also, Molly and Jake with Molly being the easily stressed red and Jake being the more cheerful blue.
* In ''{{Bonkers}}'', Bonkers (red) and detectives Lucky Piquel and Miranda (blue).
* Interestingly, while you'd expect [[TransformersAnimated Jetfire and Jetstorm]] to follow the trope (they even have red and blue color schemes, respectively), they avert the trope by both acting pretty red. Of course, they are working for [[{{jerkass}} Sentinel Prime]], so who knows how that affects their personalities.
* In ''{{Invader Zim}}'', Gir seems to show some signs of this trope, though the colors are reversed. The first few seconds when he was active, the episode "Gir goes Crazy and Stuff" and occasionally thru-out the series, Gir's colors switch from blue to red and back again. When red, he seems to show the traits of the Blue oni, and is intelligent, calm, and eager to serve his master (Often Saying "Yes my Master!"). When Blue, he acts more like the Red Oni, and is wild and over the top, with no control over his own urges or actions.
**There is also the scene were Zim hypnotises Dib, and the scene shows the ground falling apart with Zim in red and Dib in blue. Makes sense, since Zim is known for being impulsive and not thinking before acting, where as Dib is more scientific and logical (If only by a little bit)
* Corneil (blue) and Bernie (red) from ''WatchMyChops''.
* Dagget (red oni) from ''AngryBeavers'' is highly emotional and prone to Donald Duck-esque rages; stark contrast to his older brother Norbert (blue oni), who is cool-headed, and considers himself suave.
* Trevor and Aeon from ''AeonFlux''. Subverted, in that Aeon, despite being a cool, calculating, cause-oriented Blue Oni, is meant to represent chaos and anarchy, whereas Trevor, the vain, arrogant, people-oriented Red Oni, represents order and stability.
* Out of the stretchy superheroes in {{Batman The Brave and the Bold}}, Plastic Man, who wears red, is much more blunt and is okay with stealing valuables from the scene of the crime while Elongated Man, who wears purple (it's a kind of blue) is much more analytical and noble.
[[/folder]]

[[folder: Other]]
* The notion of "positive" and "negative" signs in Western astrology mirrors this trope, as does the notion of Yang and Yin signs in the Eastern flavor. Peculiarly, in both cases the Red Oni is referred to as "masculine" and the Blue Oni as "feminine".
* During the ColdWar, communist countries were represented by a red star, symbolizing the passion associated with revolution and subversion of "the system", while capitalist ones were associated with the color blue, representing the "cold" and calculating nature of the capitalist ethos.
* Choleric tennis star John [=McEnroe=] had a famous rivalry with the imperturbable Björn Borg.
* Sports:
** Ohio State (''[[ThisIsSparta FUCK! THE! WOLVERINES!]]'') and Michigan State (alumnus Mike Wallace: "They say [Michigan] is intellectual and snobby. And I guess that's true").
** Boston Red Sox (blue collar, ironically) and New York Yankees (metropolitan)
*** Like [[{{Watchmen}} Dr. Manhattan]], ''everyone'' is a hot-blooded underdog compared to the New York Yankees.
** Anaheim Angels and Los Angeles Dodgers (just for color, they both used to be blue)
** USC and UCLA
* Republicans and Democrats
*Cherry and ''blue'' raspberry. I'm looking at you, Slurpees.
[[/folder]]
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