* AlternativeCharacterInterpretation:
** Norio has gotten a bit of this. Is he actually a gay male, or could he (she?) be a [[{{Transsexual}} trans girl]] instead?
** So has Hiro-chan -- on this very wiki, even. [[spoiler:Was her attempt to kill Shunji a cruel method of [[WeCanRuleTogether trying to get Shiina to join her cause]], or was it simply her way of [[SuicideByCop forcing Shiina to kill her]]? And when she says "let's be friends" in the same scene, did that mean she never truly thought of Shiina as a friend in the first place, or did she just mean she wanted Shiina to still be her friend even while [[WoobieDestroyerOfWorlds she's messing up the world to suit herself]]?]]
** What could be the justification for the Sudo gang? Are Bungo and Satomi doing what they believe is right? There are dozens of fan-generated ideals. Sometimes goes into RonTheDeathEater territory.
* EarWorm: The opening.
* EnsembleDarkHorse: Norio gets the most fanart on pixiv by far.
* FanPreferredCouple: If fan art is anything to go by, the fanbase seems to prefer Tsurumaru with Norio and Shiina with Akira.
* MainstreamObscurity: Has a bit of a reputation for its graphic violence and {{Lolicon|AndShotacon}}-ish elements, but the ''quality'' itself is rarely discussed, probably since there aren't a lot of people who have actually read it.
* MemeticMutation: The [[https://www.youtube.com/watch?v=SIF5BLyh3Mk intro]] to the anime [[https://www.youtube.com/watch?v=JM5p8wtZxIo has a]] [[https://www.youtube.com/watch?v=C3pQYjhc2pc lot of]] [[https://www.youtube.com/watch?v=g8AxnSRyNtg parodies]], mostly due to a severe case of SoundtrackDissonance.
* MoralEventHorizon: Aki crossed it when she [[spoiler: raped Hiro-chan with a test tube]].
** Hiro-chan herself crossed it when she included her parents and Miyoko in her [[spoiler: RoaringRampageOfRevenge]]. With the former, while they were a tad strict with her, they didn't know about the bullying she was going through. With the latter, she was the only one who didn't want to take part in the test tube incident.
* SignatureScene: The test tube scene and Aki's [[spoiler: KarmicDeath]].
* {{Squick}}: Akira pressuring her friend Ishida to have sex with her and loudly masturbating after he couldn't do it. That's not the worst of it by far.
* ViewerGenderConfusion: It seems that a few readers have gone through the entire manga without realising that Norio is male.
* WhatAnIdiot: Hiroko's father. He had went to the school and root out the true cause of his daughter's suffering, he and many others would still be alive.
* WhatDoYouMeanItsNotForKids: The first chapter/episode and opening theme song aside, ''hoooooh boy!''
* TheWoobie: Akira, most prominently. Given all the crap she goes through, it's hard to not feel at least a ''bit'' sorry for her. Many other characters could qualify as well, though they tend to be either {{Jerkass Woobie}}s or WoobieDestroyerOfWorlds.