"My name is Tadakuni. I live a normal life, attending a normal school, in a normal town."
A completely normal eleventh-grade schoolboy (so he describes himself) living a completely normal life in a completely ordinary town and studying in an all boys'High School.
Attractive Bent-Gender: Looks surprisingly good in a skirt, a fact that many many artists at Pixiv seem to agree with. This was being lampshaded In-Universe; Yoshitake commented he has no signs of the male hormone when crossdressed.
Butt Monkey: Forced to play along with a love simulation, tricked into crossdressing, got punched out by the Literature Girl, went Out of Focus for several episodes, has yet to be given a surname... poor boy.
Out of Focus: He slipped out from presence in the latter half of the anime—he had zero presence in episode 9, one scene when he choked on mochi in episode 10 (outside of his Chewing the Scenery), and one eyecatch in episode 11. Episode 10's intro suggested that was because he is a Ridiculously Average Guy, but can also be justified by his part-time job at the pizzeria.
Chick Magnet: He's the only male character apart from Karasawa that females ever crush on, such as the Literature Girl and Emi.
Cloud Cuckoo Lander: Usually he just looks like a relatively normal, fun-loving teen, but sometimes he can be very weird. Two examples from episode 8:
High School Boys and Balconies: After getting jealous over a conversation he saw over opposing balconies, he attempted to reenact it that night, by climbing to his neighbour's balcony...
High School Boys and Cakes: On his birthday Yoshitake asks him what does he wanted to do for the day. He not only forgot it was his birthday, but his answer also squicked Tadakuni In-Universe: Piss in his pants.
True Companions: Amongst the trio, he subscribes to this philosophy the most.
With Friends Like These...: After a touching monologue about how he'll walk down the same path as his friends, even as panty thieves, he immediately gets sold out to Mei by Tadakuni and Hidenori, and rats them out in return.
Scars Are Forever: Keeps an ugly scar on his forehead as a reminder of an injury inflicted to him by Habara back when she was the "Archdemon". Volume 5 of the manga reveals that this is not the only one he has — he has prominent ones on his chest, his arm, and a long one down his back.
A classmate of the main characters. He's also the biggest loser in class.
Butt Monkey: The biggest of them all. Not even Tadakuni's "Out of Focus" syndrome can't match up to all the crap that happens to him, so much so even many of Yoshitake's past mishaps ended up being attributed to him.
Cosmic Plaything: Other boys spent whole chapters discussing his misfortunes — even misattributing others' mishaps to him.
In High School Boys and Kick the Can, Hidenori, Yoshitake and Motoharu played a rather physical game of kick-the-can... with his Zaku Gunpla as the can. Turns out they bought him a new Gunpla for his birthday present, but decided to destroy the older one because they're identical. Of course, the replacement is actually a bootleg, and come the next Eye Catch Mitsuo drops it off a trash bin.
A girl from Sanada West High who lives next to Karasawa. Like her Distaff Counterpart Tadakuni, Yanagin and Ikushima frequently hangs out at her house. Eight years ago, however, she was the "Archdemon," the most dreaded kid in town. After a joint effort to "pacify" her by other kids, amongst which were Yanagin and "Rubber Shooter", she has completely changed for the good.
Combat Pragmatist: She has absolutely no understanding of the concept of fair play. She doesn't punch, she gouges. She was even ready to bash Yanagin and Ikushima's heads with a large rock when they prepared to fight each other. Cue a a look of horror from both girls.
Reformed but Rejected: Everyone in town still remembers her as the "Archdemon" rather than the sweet, generic Girl Next Door she is now. Yes, she has kissed her romantic life and larger-scale friendships goodbye since third grade.
Takahiro: "Perhaps it's better for her to leave this town."
In High School Girls are Funky — Superficially, she incidentally bursted a volleyball.
In High School Girls are Funky — Megaton Poke, Yanagin had Habara try out the"punch machine" in the arcade in which the former just broke the new record. While Habara didn't get as many points as Yanagin by far... close inspections revealed a hole on the punching pad after Habara played with it, and upon asking Habara said she didn't know she has to clench his fist in the first place...
Straight Man: Towards the more oddball Yanagin and Ikushima.
Habara's oddball friend from Sanada Central High, who, like her Distaff Counterpart Hidenori, often has something to say (translate: scream) about high school boys.
Action Girl: Downplayed — she knows karate but has discontinued since middle school. This is still plot relevant as for this reason (among others) she was part of the team that barely "pacified" Habara in the past.
Celibate Hero: She hates the idea of dating in general, and has reacted violently at Ikushima when the latter wondered how can she get a boyfriend (punched her face in), or suggested that she wears glasses to look cute (threatened to rape her and eventually beat her up with a wrench).
Does Not Like Men: Played with — while she claims boys are pathetic puddles of mess, she can actually get along well with them, especially Karasawa and Takahiro, not to mention that she was one of the kids assembled to fight the "Archdemon" with intent to avenge Karasawa's terrible wound.
Large Ham: Unlike Hidenori, she is very public about it.
Meganekko: She subverts the "sweet glasses girl" archetype usually associated with the trope by being a loud-mouthed hothead. When Ikushima asked about that, she claims she only wears them not so much as a cuteness factor than as a remedy for her poor eyesight — and threatened to rape her.
"I'm not wearing them to fit in character stereotypes! I wore them because my eyes are bad!"
Morality Pet: A self-imposed one for Habara, always keeping an eye on her in case she relapses back into being the "Archdemon".
"She's probably hoping for an unrealistically romantic "Boy Meets Girl" encounter...! Can her mind shake off gravity or what? See, she's already got a distant look in her eyes. I can already tell that her romantic maiden gauge is reading full!"
Breaking down crying like a little child after a humiliating string of Epic Fails in High School Boys and The Way You Are.
At the end of High School Boys and Assertiveness, when Takahiro reminded her of how she chased Hidenori across town.
Informed Ability: Character sketches portray her as an otherwise sociable, popular girl in Sanada West High... when not sitting next to Hidenori.
Leitmotif: A lonely piano piece, which resonates well with her seemingly solitary nature, but is also non-indicative of the hilarity that ensues from her interactions with Hidenori. It was even used as the ED for the first episode.
Played for Laughs as the piece often plays for a few seconds before getting interrupted by some funny event.
Mysterious Waif: The opening seems to set her as one, and even her introduction tried to invoke (see Wrong Genre Savvy). But it's subverted for laughs when she starts to act weird and Hidenori realizes what she's trying to do.
Hidenori: "There's no reason to pretend to be cool."
Custom Uniform: Anime only. The longer she hangs around the Sanada North High School student council, the more she gains their dress sense. It comes to the point where she's not even wearing her necktie, sweater vest, or even tucking in her uniform blouse into her skirt anymore.
The Ditz: She's not the brightest bulb in town. For example, on a visit to Sanada North High in High School Girls and Panties, it took her an hour to find out the reason for a lost internet connection: the cable was never plugged on. Then she unwittingly flaunts her panties to Motoharu, the President and the Vice-President; fortunately for her she doesn't get to see them in the act, much less their horrified reaction.
Heavy Sleeper: In the unanimated High School Boys and Napping, after falling asleep in a meeting with North High's student council... The boys put more than a dozen books on her head and she didn't wake for the slightest.
Inferiority Superiority Complex: downplayed as she already has superiority undercurrents before her first visit to Sanada North, but was only fired up because she found Sanada North's Student Council a more well-managed institution than her school's.
Tsundere: Type B — she actually gets along fine with other people, like the members of the Sanada North student council, but she reacts violently to the antics of their pretty-boy Student Council President.
Both in the manga and in the anime her eyes are always blocked from the camera when they should be visible unlike the other faceless girls who just don't have them. The manga takes advantage of strategically placed sound effects and dialogue bubbles but the anime has the characters she interacts with casually obstructing her face using hands and fingers.
Super Strength: In High School Boys and Tower she can lift both Hidenori and Motoharu on her shoulders, and in High School Boys and UFO Catchers she can shake a UFO Catcher at the arcades which the main trio together couldn't even move.
Inexplicably Identical Individuals: Nago and NAGO (though their names are written differently in kanji — 奈古 versus 名護) go to the same school, and the latter looks exactly like her slim and cute reflection in a concave mirror.
A student at Sanada Central High who gets bothered by every little thing that happens around her.
Butt Monkey: Already got a taste of the Literature Girl's Yandere tendencies just because Hidenori accidentally sat next to her at their usual Artificial Riverbank. She's basically a female version of Mitsuo.
All Men Are Perverts: He's a pervert (stealing Mei's panties and bringing it around with him), and apparently so do all his friends and acquaintances, and that's not to mention his younger brother and his friends.
Shaggy Dog Story: She finally finds the chance to confess her love to Hidenori on a festival, which coincides with his last day in town. But just when she thinks she finally found her chance (after several days without much success)...
Surprise Incest: ...Hidenori makes a most surprising revelation to her: they are cousins.
"And so, I ended my summer break without being able to do a thing."