Bigger Is Better in Bed: In the wake of his viper bite (see the Crowning Moment of Funny page), we learn that this is averted (and probably inverted, though he claims otherwise, it was cold etc) by Kosukegawa, to his embarrassment, the yuks of his male classmates, and the gentle amusement of Motoko, Hino, and Tsukishima.
Can Not Spit It Out: Refreshingly subverted. The guy didn't have the courage to confess, even though it was painfully obvious to everyone. But when he was making a new year wish to have such courage, she overheard, and they started dating.
Beware the Nice Ones: Many times, people doing things they really shouldn't to Motoko ends up with an ass-kicking being dealt by the HiFuMi.
Buxom Is Better: Her classmates are either jealous (females) or appreciative (males).
Boobs of Steel: The bustiest and the most capable fighter in the entire cast.
Gag Boobs: Do not make a drinking game of how many times does she get into situations where they get exposed.
Clothing Damage: Most of this trope's occurrences happen to the alternate personalities. When she switches back to Motoko, sometimes she has no immediate idea that clothing damage occurred, which can lead to an embarrassing situation, like the one in ch. 26 when she wanted to try the "M" brooch Kosukegawa gave to her as a birthday gift.
Expository Hairstyle Change: Part and parcel of the switches between Motoko, the different HiFuMi, and Zero. Hibiki and the others play upon this a few times.
Hadaka Apron: That's the way Kosukegawa occasionally imagines Motoko as his future wife (ch. 3, for example).
Who's Your Daddy?: One of the lingering questions throughout the series, but finally resolved in ch. 59: it's Tatsuya, but the ancestors of Motoko's other "fathers" had mixed into her family tree, so she ended up with bits of their genes in her.
Split Personality Takeover: After recovering her memories of her mother's death, Motoko disappears, leaving only HiFuMi. The rest of the series is devoted to bringing her back.
Vapor Wear: Motoko is the primary victim, since Mikiri keeps bustingout of her bras every time she emerges. There is, however, one scene where Hibiki takes a precautionary measure by taking off the bra before switching to Mikiri. See also Fujiko's Bunny-Ears Lawyer entry below.
Motoko and the HiFuMi
Motoko — the core personality. Hairstyle: short Girlish Pigtails (also experimented with a loose high ponytail for a while).
Death by Despair: Motoko finally unlocks the memory of her mother's death, and it and its circumstances are so horrific, her personality just... vanishes. What makes this even more tragic is that the reveal is what she's been working toward for several chapters worth of story, and that it could have been avoided, since Kannami warned Motoko about the dangers of such a traumatic experience and told her that she should collect as many happy memories as possible to counterbalance. However, she 1) hadn't had enough time to collect that many happy memories and 2) when Motoko finally remembers what happened that fatal morning, she concludes that she doesn't deserve to be happy, so she practically withdraws into an Angst Coma.
I Wished You Were Dead: Poor Motoko. It wasn't even delayed. Her mother died instantly after she wished it, by means of a random accident.
It's All My Fault: This is Motoko's reaction to regaining the memories of her mother's death and it drives her into catatonia. Even worse we see in flashbacks that her mother had quick wits and excellent reflexes, the accident might not have claimed her mother's life if not for the hurtful words spoken by the young Motoko.
Mommy Didn't Show: Indirectly responsible for Motoko's mother's death and her split personalities.
My God, What Have I Done?: With the interesting twist that she didn't do it — it was purely magical thinking, but she was too young to realize it, and that part of her never got a chance to realize it.
Does Not Know Her Own Strength: She easily squashes a rubber ball to shreds (and considering Kousukegawa could barely even squeeze it), then when someone tries to trip her, said person ends up being thrown over as if by Megaton Punch by her mere running stride.
Also results in a The Door Slams You situation when, after being trapped in a sauna with Kousukegawa, she kicks the door open, which slams right into the perpetrator who locked the door, sending the latter flying into a jacuzzi.
Perhaps the most ridiculous instance of this is her First Kiss with Kousukegawa in ch. 1, which literally hurt.
Glass Cannon: She has the greatest offensive power among HiFuMi, but lags behind Fujiko and Mikiri in speed and defense, respectively.
The Tease: Only to Kosukegawa, and almost always serious about her offers. There's also her promised gift for Kosukegawa's next birthday, which she asserts that it will be "better" than the kiss she gave him for the birthday she already missed. Evidently, she got Motoko's sex drive, but Motoko kept the inhibitions.
Fujiko — Cool-headed (almost cold, at times) and calculating. Soldier/swordswoman. Hairstyle: tidy hair, asymmetrically swept to one side, bordering (but not actually reaching) Peek-a-Bangs style.
Improbable Aiming Skills: In ch. 35, she manages to fire a bullet into the chamber of a gun. From about ten feet away. In the split second the chamber was open, when the guy fired it.
Improbable Weapon User / Improvised Weapon: Even coin tokens are dangerous in her hands. And if you try to threaten her with a 40-member biker gang, she needs only two nails to set all their fuel tanks on fire - one to punch a hole in a fuel tank, and one to make a biker drop his cigarette.
Breast Expansion: Her boobs grow to indicate that she's 'come out', often snapping Motoko's bra. Explained as being because of a change in "muscle tension" - her pectoral muscles are more "tightened" than normal, thus pushing her breasts further out than usual.
Alternative Character Interpretation: invokedKannami himself, in one of the final chapters of Volume 9, reveals to Kousukegawa that "Motoko" may be nothing more than a host personality, constructed from scratch to believe herself as the original one in order to deal with the world that Zero - the real, original Motoko according to this scenario - had retreated from. The implications of this hypothesis being true are earth-shaking, to say the least.
Deadly Upgrade: Her extreme lethality is a result of pushing past her physical limits; the fact that, at first, she only comes out when the other three personalities have been thoroughly beaten, usually meaning that their shared body is considerably damaged by that point, does not help. In her first in-story chronological appearance, back when she was still a child, she remained in control for only three minutes; the time limit has since increased considerably. Later on, Hino reveals to Ginga that Zero could push her body so far past its limits that severe muscle and joint damage, or even fatal heart stress, could occur.
Berserk Button: They each have their own unique buttons, which have the side-effect of causing them to temporarily (for now, at least) merge with Zero.
Fujiko's is the first to be revealed: Killing Kousukegawa in cold blood. He was only knocked out, though; it's the red-colored juice that spilled from his pocket that made it look like he was bleeding to death. Fujiko was understandably mortified at her overreaction.
Next comes Mikiri's: Ruining a recently-deceased old woman's odango, when said woman was very kindly and generous towards her.
Confusion Fu: When they battle Tatsuya, they gain the upper hand by switching personalities on the fly, making them more unpredictable. It works for a while.
Roaring Rampage of Revenge: This happens when one of the HiFuMi's Berserk Buttons is pushed, causing her to merge with Zero and lash out. Mikiri's was violent but semi-comical in its ending (though it did nearly result in a literal backbreaker move). Fujiko's was chilling in its cold, calculating near-lethality. Hibiki's was short-lived, but brutal... and ended up being the most traumatic, since it triggered the remembrance of Motoko's mother's death, causing Motoko to essentially vanish, leaving only the HiFuMi and possibly Zero behind.
Talking to Themself: Hibiki, Fujiko and Mikiri are aware of themselves all the time, can communicate between themselves, even if the Motoko personality is the active one (and they often comment on what Motoko is currently doing), and can freely switch between themselves. However, the Motoko personality can't do any of these things.
Theme Naming: The first syllables in Hibiki, Fujiko and Mikiri are extremely short abbreviations of hitotsu, futatsu and mittsu, the Japanese numerals for "1", "2" and "3", respectively. With that in mind...
In-Series Nickname: ...it is no wonder that they are collectively referred to as "HiFuMi".
And then of course comes the fifth alter "Zero", who is not only the HiFuMi's predecessor (she was formed due to Motoko's traumatic experience of witnessing her mother's death), but is heavily implied to be the original, true Motoko Gettou.
Two-Person Love Triangle: There are small implications that Hibiki and Fujiko are jealous of Motoko for being the one to interact with Kosukegawa the most.
Butt Monkey: Not only does she suffer from the Huge Schoolgirl complex, she gets put into various embarrassing situations over several chapters. She also suffers from an inferiority complex, because her job description (she's a kunoichi) includes fighting abilities, but because of her lack of experience she gets beaten by MoeishMartial Pacifist Izuru in ch. 28, who is merely a talented amateur, or gets herself in ch. 46 into a situation where she must run away from fighting to avoid being discovered by the police. She even lampshades this in the latter instance. Chapters 54 and 55 take it to a cringeworthy degree.
Huge Schoolgirl: 175+ cm. (5'9" for you Americans.) Moderately above average for Caucasian women, very tall for a Japanese woman.
Ninja Maid: Wears a maid outfit at a school festival. In this case it's not a Fanservice, but done for comical (and Butt Monkey) effect. What makes it more interesting is the fact that she is actually a ninja (or kunoichi, if you prefer this term) on a covert assignment.
Oh Crap: Has this expression quite a lot as a result of her Butt Monkey and/or Huge School Girl situations. One prominent example is in ch. 19, where she's completely horrified at the thought of being seen as an Otaku Surrogate (which is not even intentional on her part to begin with).
Cute Bruiser: Lest we forget, she was introduced carrying her kill — a full-sized leopard — over her shoulders.
Innocent Fanservice Girl: She doesn't have a lot of modesty, although she didn't start wearing concealing clothes until she came to Japan... and sprouted.
Long-Lost Relative: She is revealed to be a cousin of Kosukegawa through his great-grandfather.
Samus Is a Girl: A topless "Samus", no less, as at her first appearance, she was still living on the island, not yet introduced to civilization and clothes.
Vitriolic Best Buds: Ginga and Hino spent many years of their childhoods together, and are close friends, but Ginga was, at first, furious with Hino for the latter's perceived betrayal of Ginga's people's customs (she left the island rather than remain to serve as the Gadam).
Clothing Damage: Hino (and her clothes) get cut up pretty badly in ch. 34 when she accidentally leaps into a thornbush. Later, during a sports carnival contest she has her shirt and bra accidentally ripped off.
Vitriolic Best Buds: ...with Ginga (see above). Hino isn't angry with Ginga at all, but she doesn't hold back when defending herself from Ginga.
Yamato Nadeshiko: Because of this, and because she is a Kamen Raider fan like Kosukegawa, at first it seems that she is bound to become a Relationship Sue for him, which saddens Hibiki (and later, Motoko), but eventually it turns out that Kosukegawa's love for Motoko/HiFuMi is far too steady.
She's also an incredibly gifted Aikido prodigy. Her present fighting skill developed as a result of having to survive in the wilderness of a tropical island for much of her youth.
Blood Knight: As well as Hibiki, Tatsuya, the karateka "father" who trained her and Matoko's biological father, will fight anyone who looks strong for the fun of it. Even Ginga. Not to mention the fact that Motoko's other two fathers kept Zero secret from him so he wouldn't fight her to the death. Ch. 52 takes this Up to Eleven, when he helps a convicted psycho murderer break out of prison just so he can fight him to the death...which takes three minutes.
Color-Coded for Your Convenience: Starting with Hifumi, all fighters are revealed to be categorised into colour-coded combat styles, or a combination of two or more. Tsukishima especially seems to be obsessed with achieving her colour title, and is baffled when fights don't quite follow these rules.
During the "bring out Zero" ploy", one of the fighters (also a member of Ginga's tribe) holds Mikiri's head underwater just long enough to knock her unconscious. The Improbable Weapon User below tries to take out Fujiko by bleeding her out through strategic cuts...and he nearly succeeds.
The Hero: either Kousukegawa, Motoko, or both; as nominal leader(s), at least. If Motoko's "Tomato in the Mirror" theory is true, however, then Zero might qualify as a subversion, considering her... less-than-sunny disposition.
The Lancer / The Big Guy: Hibiki, who is a stark contrast to the shy and noncombatant Kousukegawa and Motoko.
The Smart Guy: Fujiko, being more strategy-oriented and technical than Hibiki and Mikiri.
One enemy uses his fingernails, a technique used by some Shaolin monks.
Sora Uzuki uses a kusarigama-like weapon consisting of sharpened keys on a wire.
Long-Lost Relative: The leader of the apparent-ninja clan that includes Sora and Tsukishima is Motoko's grandmother.
MeaningfulTheme Naming: Aside from HiFuMi, there is also evidence of other suspicious occurrences discovered by Kannami in chapter 49, but clues can be found earlier on, if the reader pays attention to the meanings of certain kanji characters.
Neighbourhood Friendly Gangsters: Aizawa, who is younger than he looks, a former thug who got into high school around the same time as Ginga. While looking to establish his rep, he got tagged with the title of School Guardian by accident, and then finds out that not only do all the strongest fighters in their school outclass him, but they are also girls.
Parent with New Paramour: The young Russian woman Anna, besides being a talented disciple of Takezou (Motoko's jujitsu father, who "created" the Mikiri personality), is also apparently his girlfriend. When she jokingly tells Motoko about the possibility of becoming her stepmother, Motoko freaks out.