[[quoteright:255:https://static.tvtropes.org/pmwiki/pub/images/Onidere-demon_head_2118.png]]
[[caption-width-right:255:[[NamesToRunAwayFromReallyFast The Demon Head Gang]] [[note]]from left to right: Momo, Mitsuki, Yuna, and Saya, with Tadashi on the far right.[[/note]]]]

''Onidere'' is a manga by Crystal na Yousuke, which ran in ''Magazine/ShonenSunday'' from 2008 to 2011.

Tadashi Iwamato is a second-year in junior high, a member of the handicraft club, and someone who enjoys knitting. He's in a relationship with Saya Ikushima, who happens to be the leader of an [[{{Delinquents}} all-girl gang]] and would get killed if anybody finds out.

Not to be confused with ''Manga/YandereKanojo'', which is only strikingly similar to this series in setup.

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!!'''This series contains examples of:'''

* AcquiredPoisonImmunity: [[spoiler: In one chapter, a potion causes everyone to turn into a baby except Tadashi. Shu says that due to him eating so much of [[LethalChef Saya's cooking]], his stomach has developed the ability to digest ''anything''.]]
* AllergicToLove: In a roundabout way. Saya's feelings for Tadashi are so intense, that if he does anything she finds even the slightest bit arousing she suffers a nosebleed so massive that she may actually die from blood loss
* AmazinglyEmbarrassingParents: Tadashi's mother is hilariously embarrassing.
* AngstComa: [[spoiler: Saya is reduced to one when Tadashi is forced to break up with her, despite the fact that it was only supposed to be temporary and she planned it in the first place!]]
* AssKicksYou: After Yuna and Student Council President are thrown towards the ocean by the Kraken during Summer vacation, the president lands on a raft and lives.....only to be hit by Yuna's Buttock at a ''very'' high speed. Good thing he's [[NighInvulnerability invincible]]!
* AstonishinglyAppropriateAppearance: Saya and her "horns". Sort-of-subverted considering the rest of her personality.
* BadassAdorable: Saya is adorably sweet and shy with regards to Tadashi. She can also split a building.
** Mitsuki definitely counts. And even Yuna can be cute when she wants (which isn't often).
* BambooTechnology: Kenji Taketori's company, Taketori Financial Combine, specializes in making bamboo products. Including functional bamboo rocket ships.
* [[BeachEpisode Beach Arc]]: Chapter 63-78. Which also manages to squeeze in a...
** HotSpringsEpisode
* BearsAreBadNews: Other than Mitsuki's liking for bears, a [[ShroudedInMyth common myth]] about Saya is that her boyfriend is a bear. Unless Tadashi has a TomatoSurprise sometime soon, it's not true.
* BeautifulAllAlong: Yuna has always been good-looking, certainly, but once she loses the delinquent clothes and lets down her hair she starts skirting EvenTheGirlsWantHer.
** [[spoiler:Momo when she takes her mask off.]]
* BecomingTheMask: A (literal?) case with Momo.
* BerserkButton: The Haou-Sou members (three out of four, anyway) have berserk buttons of their own, all related to the opposite sex. Aoi goes violent when she thinks a boy hears her Akita accent, for example. Having masks on prevents that, thankfully.
* BewareTheNiceOnes: Several times, with Saya, Shuu, and even Tadashi.
* BigEater: Mitsuki is able to eat three kilograms of snacks.
* BrattyHalfPint: Mitsuki.
* CampGay: Oh sweet Jebus, [[spoiler: Yumi]] to the MAX!
** AttractiveBentGender: you can ''never'' tell what gender that person was, at first, anyway.
* CassandraTruth: [[spoiler: Tadashi reveals their secret to Saya's dad and the other two Demon Head members!]] But nobody believes them...
* ChekhovsGun:
** In Chapter 30 Momo attacks the '''Student Council President''' with an attack that invokes TheFourGods, and when that doesn't work she puts on a beak-shaped mask and draws a sword. Later she uses the same mask and sword when she [[spoiler:reveals her identity as one of Hao-Su, which just happen to be themed after TheFourGods]].
** Momo's love for the cartoon bird Piyouta might also count, since [[spoiler:she represents the Phoenix in the Hao-Su]].
* CloseCallHaircut: [[spoiler:Momo, upon her revelation as TheMole]], stops short at cutting Saya's head with a katana. Her hair on that side wasn't so lucky. So Saya decided to make an ImportantHaircut out of it. [[spoiler:Interestingly, [[HairReboot her hair grew back]] with the Poseidon Wakame.]]
* CompanionCube: The Student Council President's '''Statue of Justice'''.
* CreepyCrossdresser: [[spoiler:Yumi.]] Surprisingly, the only man who sees through his disguise immediately is [[spoiler:'''the Student Council President''']]!
* CrouchingMoronHiddenBadass: [[spoiler:The Treasurer's hair turns white when she snaps.]]
* CuteBruiser: Mitsuki.
* {{Determinator}}: the President in his misguided quest for '''Justice'''. The only things that could really affect him are when his sense of '''Justice''' is compromised [[spoiler: or Saya in [[SuperpoweredEvilSide Hyakki Yagyou mode]]]].
* DontTellMama: Don't Tell Little Sister: Saya wants to keep her delinquent status a secret from her little sister.
* DualWielding: Yuna used two [[WoodenKatanasAreEvenBetter bokutos]] as her weapon
* EasyAmnesia: So easy, getting deeply embarrassed will do it.
* EmbarrassingFirstName: Saya's full name is actually ''[[spoiler:[[IronicName Angelica]]]]'' Saya Ikushima.
* EmotionlessGirl: Momo, who rarely seems to be agitated by other people's behaviour... [[BerserkButton Except when you interfere with her side job! ...or her favorite show.]]
** She has emotions, there just harder to notice on account of her being both TheFaceless and TheVoiceless.
* EngagementChallenge: One of the later plots involves 4 of Saya's possible fiances (the fifth couldn't make it) competing to see who would get her hand in marriage. The challenge? Avoid [[spoiler: getting caught by [[TheJuggernaut her father]].]]
** [[spoiler: The challenge that Saya gave Tadashi to become her boyfriend also counts.]]
* EpicFail: In the election between Yuna's brother and '''student council president''', the president was so hated that he got ''-2 votes''.
* EveryoneCallsHimBarkeep: The '''Student Council President'''.
** Although his real name, Tomoe Kinoshita, is hardly a secret.
* {{Expy}}: Tadashi Mom sometimes feels like an older version of [[Literature/ToraDora Minori]].
* ExtremityExtremist: Souta, who falls in love with Angie (Saya's alter ego), fight only with kicks so powerfull that managed a standstill Saya all out.
* ExtremeOmnivore: Tadashi is a specific type. He'll eat anything that Saya will cook for him, regardless of how much suffering he endures.
** Saya's family seems to have a strange standard for taste as Saya's sister can not only drink her tea without ill effect, but actually enjoys it. Of course, Saya thinks everything she cooks is delicious.
*** Actually Saya faints after tasting her own cooking. [[spoiler: She dreams that it's delicious and believes that to be reality.]] Tadashi doesn't have the heart to tell her otherwise.
** Saya's [[spoiler: dad]] is a subversion, and [[spoiler: actually ''loses'' in an eating contest with Tadashi]].
* EyepatchOfPower: Yuna... although it turns out that the only thing wrong with the eye underneath it is some mild eye strain. The patch is actually a cooling pad.
* TheFaceless: Momo is never seen not wearing her bandana [[spoiler: until the very end.]]
* FirstKiss: Tadashi and Saya's first kiss [[{{Squee}} overloaded her emotions so much]] that she fainted and completely forgot that it ever happened.
* FluffyTamer: Mitsuki, where bears are involved.
* [[TwoPersonLoveTriangle Four-Person Love Hexagon]]: Yes, it is as screwed up as it sounds.
* TheFourGods: the Haou-su, according to Website/TheOtherWiki, representing each deity.
* GargleBlaster[=/=]MasochistsMeal: There are only two people who would willingly eat Saya's prepared meals. One does it for love, and the other actually ''likes'' it.
* GenderBender: President Tomoko Kinoshita has arrived! But (un)fortunately it was [[AllJustADream just Tadashi's dream]].
* GenerationXerox, in two cases:
** The '''Student Council President''''s grandfather is basically him with a moustache and beard.
** Tadashi and his father are nearly identical. Not just the faces, but also the constant "wtf have I got myself into?" jaded expression.
* GeniusBruiser: In a surprising twist, Saya has the 2nd highest grades in the class [[note]]The Student Council President has the highest.[[/note]].
* GivingUpTheGhost: Saya's mother suffers from a disease that causes her soul to slip out of her body and fly away.
* GoKartingWithBowser: They're ''all'' together for the [[BeachEpisode beach arc]]. Except Yumi and Aoi for some reason.
* HatesMySecretIdentity: Souta hates Saya, but is [[LovesMyAlterEgo interested]] in [[PaperThinDisguise Angie]].
* HeadbuttThermometer: Tadashi eventually uses this on Saya which (of course) causes her to pass out.
* HeirToTheDojo: Yuna's main motivation to become stronger is to be able to inherit her family's dojo so her [[DudeLooksLikeALady effeminate brother]] won't do it. However, while she can't stand the idea of some effeminate person taking over the dojo, she's even more dismayed by the fact he's actually stronger than her.
* HypocriticalHumor: '''The white haired Student Council President''' thinks black hair is the perfect Japanese idea and repeatedly "corrects" the hair color of offending students.
* IdenticalGrandson: '''The Student Council President''' is a spitting image of his grandfather, in looks ''and'' personality.
* ImagineSpot: Saya's usually occcur when she daydreams about Tadashi doing something sweet for her, and her mental image of him is either {{Bishonen}} or hilariously [[HugeGuyTinyGirl gigantic]].
* ImplacableMan: The President walks through Momo's traps like they weren't even there.
** [[spoiler: Saya's Father]] who can receive a KillSat ''without'' even notice it and can stop Saya with a single hand move. So far nothing has managed to even scratch him [[spoiler: except Saya's food who brought him down in half a plate]].
* ImTakingHerHomeWithMe: Mitsuki's default reaction to anything that looks like a bear.
* IneffectualSympatheticVillain: The Haou-su quickly degraded into this. They would have easily gone on with their plan to [[spoiler:separate Tadashi and Saya]] by transferring to their school, if it weren't for the fact that they could barely stand, ''literally'', being in the same place with members of the opposite sex.
* IntoxicationEnsues: And it was because of ''[[MushroomSamba mushrooms]]''.
* JusticeWillPrevail: The typical attitude of the Student Council President. Backed up somewhat by his ludicrous '''Justice'''-based invulnerability.
* KidAnova: Kenji Taketori, Saya's [[spoiler:[[ArrangedMarriage first fiance]]]].
* KillSat: After a younger Saya misconstrued her dad's words as a challenge for her to defeat him, she had a laser satellite commissioned to shoot at her dad every time she says "defeat the old man." Yeah...
** And it ''still works'', years later. It's been blasting him for years! Just exactly how {{Nigh Invulnerab|ility}}le ''is'' this family?!
* TheKnightsWhoSaySquee: Saya does this a lot for Tadashi.
* LargeHam: '''The Student Council President.'''
* LethalChef: Saya's cooking could inflict greater pain than actual poison. A RunningGag is having people who taste Saya's cooking FlashBack to the greatest pain they've experienced in their life and calculating how much more the pain her cooking brings in comparison.
** Her tea is so bad that it makes people flashback to ''the rest of her cooking''.
* LickedByTheDog: Dogs love Saya. Too bad she's terrified of them.
* LittleMissBadass: Mitsuki is a cute [[TokenMiniMoe little girl]] who loves bears and her [[{{Oneesama}} Anego]]. She's also a member of Demon Head who regularly takes down multiple delinquents and tames bears.
* [[spoiler: LivingEmotionalCrutch: Tadashi is one for Saya. See AngstComa above for proof.]]
* LockedInAFreezer: Subverted. Saya and Saki the Treasurer gets trapped in a cave-in. Well, they would be trapped if Saya didn't just clear away the rubble in one blow.
* LoveTriangle: Played straight, and also humorously subverted and lampshaded by the narrator. [[spoiler: Saki is in a love triangle with Tadashi and Saya, but in chapter 83, Saya forms a Love Triangle ''with herself'' by disguising herself as a different person and trying to steal Tadashi away from/for herself. Made all the better by the fact that Tadashi saw through her 'disguise' in seconds and has ''no idea'' what's going on.]]
** [[spoiler:Which then causes ''another'' and even more confusing love triangle when new character Hanamura falls in love with 'Angie', except Saya still hasn't figured out that Tadashi knows that she and Angie are the same person, so he can't admit he likes Angie without hurting Saya's feelings, but also can't let Hanamura date Angie because she's really Saya. Ah, love is beautiful, isn't it?]]
*** [[spoiler:That's nothing. Now Saki's doing it under the alias Kurosaki. Making it a LoveDodecahedron.]]
** LovesMyAlterEgo: really, ''really'' gets nuttier by the later chapters.
* LudicrousPrecision: How long can Tadashi hug Saya without her passing out? 7 seconds.
* MadeOfIron: Considering the punishment Tadashi takes from Saya, he still manages to survive.
** It gets even more exaggerated with the President, who could take attacks from the Demon Head members without a scratch.
* MajorInjuryUnderreaction: Saya takes some serious injuries (usually from herself) that she barely registers, while making her boyfriend panic. To elaborate she hits her head so hard while apologizing that she causes a quake that registers a 3 on the Richter Scale. She does not even say ow or pay any attention at all to the blood coming out of her head.
* MaskPower: Lets Momo turn from deliquent into mild-mannered, Pyouta-bandanna-wearing Sumomo-chan and back.
* MistakenForBadass: Tadashi is mistaken for this for making his girlfriend faint from [[{{Squee}} a rush of emotion]]. Ended up as Vice-President of the Student Council.
* MistakenForGay: Amane and Akihito, due to peculiar habits stemming from their issues with the opposite sex.
* TheMole: [[spoiler:Momo.]]
* MurderTheHypotenuse: [[spoiler: Saki finds out that Saya and Tadashi are going out. Saya's response is to try and kill her so she doesn't have to [[SuicidePact kill Tadashi]]. When that fails, Saki just becomes a SecretKeeper instead.]]
* NighInvulnerability: The President, courtesy of him being an [[JusticeWillPrevail ENVOY OF JUSTICE]]!!
* NoseBleed: Saya must be the grandmaster of these.
** A memorable scene had her having a fountain of a nosebleed. Next panel, she's back to normal... [[spoiler: only there's three overfull buckets of blood nearby.]]
*** That's nothing. Try an ''entire room!'' It even threatened to drown Mitsuki and Yuna. Saya don't give a damn conservation of mass.
* {{Ojou}}: Saya's also the daughter of the CEO of the [[MegaCorp Glow Island Group]].
* {{Oneesama}}: Mitsuki and Cupid towards Saya. Saya wants to maintain this image for Cupid.
* OddlySmallOrganization: For someone who took down multiple delinquent kings, the Haou-Sou is composed of only three people. They had [[spoiler:Momo before she left them]], but you'd think they'd have some underlings at least.
* OnlySaneMan: Tadashi. One look at the other characters should explain why. [[spoiler:It got especially bad when Saya, Mitsuki and Saki [[PaperThinDisguise disguised themselves and underclassmen]], and then an ''actual'' underclassmen appeared... Who has a crush on Saya's alter ego. Meanwhile, the girls think their plans are foolproof, the new kid (Whose name is Hanamura Souta, by the way) is totally out of the loop, and Tadashi is pretending to be none-the-wiser to avoid hurting anyone's feelings.]]
* PaperThinDisguise: Just changing her bandanna makes Momo unrecognizable to her normal classmates.
** And then there's Saya herself in recent chapters, when masquerading as "Angie". She ''thinks'' that she's fooled everyone. Well, she probably did, except for Tadashi...
** And now Mitsuki's getting in on it with her 'Mitsu-gie' disguise, which consists of... a different hairstyle. It sort of hurts her chances that she doesn't ''really'' understand why she's even in disguise to begin with.
** And now ''Saki's'' doing it too, with longer hair and a different uniform. Poor [[OnlySaneMan Tadashi...]]
* PersonOfMassDestruction: Saya´s power is just ridiculous! She caused a magnitude 3 earthquake [[spoiler:by accident, ''WHEN SHE WAS APOLOGIZING!'']]
** [[spoiler: And she inherited it from her father.]]
* PintSizedPowerhouse: Hanamura Souta is barely taller than Mitsuki (and younger) and the only (ex)delincuent so far who managed to face an all out Saya to a standstill.
* PitbullDatesPuppy
* ThePowerOfFriendship: Momo definitely felt it.
%% ZCE * PrettyBoy: Tadashi, in Saya's {{Imagine Spot}}s, at least. The local TinTyrant as well, although only part of his face was seen.
* ProductPlacement: Mcdonald's, in the Chapter 70 {{omake}}.
* RedEyesTakeWarning: Saya.
--> The young girl squashed by the sliding door they knocked over was the being once dubbed a demon and feared. That demon's eyes then… went to transform from a smoothing ultramarine to a bitter vermilion.
* TheRival: [[spoiler: Tadashi and Saya's cover evolves into this.]]
* RunningGag: A lot of them. They include, but are not limited to: Saya fainting with Tadashi-induced arousal, Mitsuki attempting to molest her, Yuna eating poison mushrooms, Saki gobbling ridiculous amounts of chocolate and the Student Council President just generally being {{Nigh Invulnerab|ility}}le.
* SandInMyEyes:
-->''Please ignore the water coming out of my eyes.''
* SatelliteLoveInterest: It's been argued whether Saya, Tadashi, or ''both'' fit this--both are primarily characterized in terms of their connection to each other.
* ScrewDestiny: In chapter 77, a fortune teller whose predictions have always been accurate (according to him anyway) uses his crystal ball to show Tadashi and Saya that their love is doomed. Then he sees another vision of the two still together. He interprets this to mean that the unhappy future he first saw could still be averted, and informs them of such.
* SecretSecretKeeper: Momo actually knows about Saya and Tadashi's relationship, and helps them keep it a secret. Even when they don't know that she knows.
** Which becomes a plotpoint later on. [[spoiler:Since she was ([[HeelFaceTurn once]]) the Hao-su's [[TheMole mole]], ''they'' were aware of it themselves, and are planning to destroy the relationship.]]
* ShoutOut:
** Saya's [[SuperpoweredEvilSide Hyakki Yagyou mode]] reminds one of a certain [[VisualNovel/{{Tsukihime}} Moon Princess]].
** Also in chapter 136, one of the gang leaders is named [[Manga/ThePrinceOfTennis Echizen]] of [[Magazine/ShonenJump Jump]].
* SickeninglySweethearts: The overly romantic couple seen at the beginning of chapters.
** Saya and Tadashi everytime they are alone.
*** And Yuna is fast diving becoming this for the president. [[ObliviousToLove Too bad that the president is completely ignorant of this fact.]]
* TheSilentBob: Momo never speaks a word, or even really expresses herself through body language besides her signature pose.
** [[spoiler: She finally speaks in the final chapter to give a TearJerker plea to her friends.]]
* SinisterScythe: The hidden function of Mitsuki's [=KumaPiko=] Hammer.
* SkinshipGrope: Mitsuki towards Saya.
* {{Sarashi}}: Yuna wears one in lieu of a shirt.
* SuicidePact: Part of the agreement Saya has with Tadashi is that if anyone finds out about their relationship, she'll kill him and then herself.
* SuperpoweredEvilSide: If you think Saya's strong now, you '''do not''' want to [[HeroicBSOD push her]].
* SuperSpeed: Tadashi moves so fast that he creates afterimages when he cleans.
** This trope taken to the max when Tadashi helps Saki in student council office, where he is moving so fast that his afterimages seem to be independent clones.
** It also only takes him five seconds to create a complete outfit.
** Saya also has this, being able to run at over 250 mph while pulling a cart full of people.
* SuspiciouslySpecificDenial: From Angie [[spoiler: who is not Saya]].
** And from the author: "Because of various circumstances, here's chapter 99.5! Th-this isn't to stall the number of chapters or anything!"
* TeamDad: Shuu, even [[LampshadeHanging referred to as such]].
* {{Telepathy}}: Saya's fiancé appears to have some form of this, limited to letting him say an appropriate line for seducing a girl.
* TinTyrant: And he's a nice guy.
* {{Tomboy}}: Yuna, a DualWielding thug with a hidden taste for girly clothes.
* TooDumbToLive: Piyouta, the feathery hero of Momo's favorite cartoon franchise.
--> ''"I suspect there's [[RightBehindMe something behind me]], but I'm too sleepy, ~piyo . . ."''
* TrademarkFavoriteFood: Saki ''loves'' chocolate. To the point of using it as a universal topping.
* TrueCompanions
* {{Tsundere}}: The whole series is an interesting take on the Tsundere story, with Saya as a Type B. She's actually pretty sweet towards Tadashi normally, but gets violent to prevent the other Demon Head members from finding out.
** Later, ''[[spoiler: Yuna]]'' becomes a Type A with regards to [[spoiler: the Student Council President]].
** Also, The Treasurer to some degree.
** And at last, Saya's ridiculous [[SecretIdentityIdentity secret identity]] [[LovesMyAlterEgo mess]] has culminated in Tadashi himself acting tsundere.
* TheVoiceless: Momo has never once spoke a word in the entire series.
** Except for those times where [[spoiler:she impersonates the president's voice.]]
** [[spoiler:And finally speaking for real and without her mask in the end.]]
* WeirdnessMagnet: The Student Council President regularly draws bad spirits to him and needs to be exorcised by Secretary Shuu.
* TheWoobie: Saya's suffering from being kept back from being with her beloved Tadashi makes her come awfully close to this at times.
* WhyDidItHaveToBeSnakes: Saya has Cynophobia (fear of dogs). It's played entirely for laughs.
* {{Yandere}}: Suzune Yumi, Yuna´s [[spoiler:big [[UnsettlingGenderReveal brother]]]]! Kenji really is an unlucky guy...
* YaoiFangirl: '''''[[spoiler:Misako]]''''', of all people really likes Taketori's "relationship" with Yumi.
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