* FanFic/DungeonKeeperAmi features [[NobleDemon Jadite]] and [[BadAssBookworm Ami]], occasionally. Jadeite also fills the same role to [[MissionControl Cathy]]. On the other hand, Tiger is a red oni to everyone, even Jadeite.
* In the Great Chicken Miasma's Mario fanfic ''BetterOffAlone'', the young Yoshi Waffles is the Red to everyone else in the group's Blue.
* In the fanfic [[http://www.fanfiction.net/s/6984913/1/Disgaea-Jewel-of-the-gods Disgaea: Jewel of the Gods]], Laharl is the red oni to Adell and Mao's blue oni.
** Adell can also, arguably, qualify as the red oni to Mao's blue oni.
* ''FanFic/WinterWar'' gives us Ikkaku and Nanao, the co-leaders of the Hueco Mundo mission. Ikkaku is a HotBlooded BloodKnight with a newly acquired habit of [[TheNicknamer giving nicknames]] and a physical fighter with no aptitude for kidou. Nanao is a [[NoSenseOfHumor serious]], methodical, control obsessive BadassBookworm and kidou specialist who so far has avoided hand-to-hand combat.
* ''[[FanFic/ErisGame Eri's Game]]'' has Eri as the Red Oni and her best friend, Shiki, as the Blue Oni.
* ''Fanfic/Swing123AndGarfieldodiesCalvinverse'' has [[MadScientist Dr.]] [[StupidEvil Brainstorm]] as the red oni, with his {{foil}} [[SnarkyNonhumanSidekick Jack]] being the blue.
** The main cast also has this distinction. From most red to most blue, they are as follows: [[color:#ff0000:Socrates]], [[color:#d5002b:Calvin]], [[color:#aa0055:the MTM]], [[color:#5500aa:Hobbes]], [[color:#2b00d5:Sherman]], and [[color:#0000ff:Andy]].
* ''FanFic/ToKillAThief'' has [[Manga/DeathNote Light Yagami]] as red due to [[AxCrazy being crazy]] with KnightTemplar ideas, while his partner, [[KamikazeKaitouJeanne Miyako Toudaiji]], is blue due to [[OnlySaneMan being sane]] with ByTheBookCop tendencies.
* In ''Fanfic/WhiteRain'', it is Sasuke who is the Red Oni to Naruto's Blue, strangely enough. Their relationships also have the same distinction.
* ''Fanfic/TheWizardInTheShadows'' has Harry as the Red Oni to Aragorn's blue.
* ''FanFic/{{Apprentice}}'' has [[{{Manga/Naruto}} Sasuke]] and [[ComicBook/ArchieComicsSonicTheHedgehog Mecha Sally]].
* ''Fanfic/ChildrenOfTime'' has [[WesternAnimation/SherlockHolmesInTheTwentySecondCentury Beth's]] red to [[Literature/SherlockHolmes Holmes's]] blue.
* The dynamic between [[spoiler: Chaos]] and Takato in the ''FanFic/TamersForeverSeries'' is an interesting inversion of this trope. [[spoiler: [=ChaosGallantmon=]]] has blue highlights on his armour, while Gallantmon has red highlights, and [[spoiler: Chaos]] is also much more ruthless than Takato, but surprisingly enough, ''Takato'' is actually the Blue Oni, being much more subtle and thoughtful than the impulsive [[spoiler: Chaos]].
* ''FanFic/WorkingTogether'' has [[Anime/DigimonTamers Rika Nonaka]] as the Red Oni and ArchEnemy [[WesternAnimation/JackieChanAdventures Valmont]] as the Blue Oni.
* Vale Whitaker, the ShrinkingViolet heroine of the HungerGames fanfiction ''Fanfic/SomeSemblanceOfMeaning'', is the Blue Oni in contrast to several Red Oni in the story, including [[HotBlooded her sister Maybelle]], [[KidSidekick her district partner]] [[MouthyKid Kit]], and FieryRedhead [[ArcherArchetype Fen]].
* ''Fanfic/KitsuneNoKenFistOfTheFox'' gives us Suigetsu and Jugo, red and blue respectively. Suigetsu is HotBlooded, while Jugo's more calm and methodical.
* The ''Manga/MedakaBox'' fanfic ''Fanfic/WorldAsMyth'' has the friendship between the violent [[AxeCrazy Unzen]] and the phlegmatic [[TheStoic Choujabaru]].
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