History Manga / DissolvingClassroom

* ApologeticAttacker: In a way, although the attacks themselves are apologies. Yuuma apologizes constantly, which only does harm, but it appears there is genuine remorse behind them...but this is because [[spoiler: he's speaking to the devil, whom he may deeply regret getting involved with]].

* BittersweetEnding: More bitter than sweet, as while [[spoiler:Yuuma and Chizumi are implied to have been killed by the animated liquid remains of their victims, and thus their souls are now in hell, thousands (if not millions) of people are implied to have been killed by watching the news feed of the press conference and hearing Yuuma's apologies]].

* KillEmAll: [[spoiler:The story ends with Yuuma apologizing on national television, causing a melting massacre of all the journalists there, a struggling Keiko, as well as anyone watching the press conference. Then the souls of Yuuma and Chizumi's murder victims overcome them and murder them in turn, as the Devil sadistically watches]].

* {{Bishonen}}: Yuuma is noticeably more attractive than the rest of the male cast, and his looks are one of the first things that women notice about him. This makes it much easier for them to let their guard down when around him.

* AdultFear: Yuuma in one chapter starts dating several girls, complimenting their looks. [[spoiler:Every time that he does it, their brains and faces melt]]. At one point a girl's parents insist on taking her to the hospital because it looks like she developed serious cancer.

* RealityEnsues: Multiple incidents crop up around Yuuma and Chizumi, and they are eventually hunted down by the media for an explanation. [[spoiler:Unfortunately, the media hunt doesn't end up well for the people who finally get their apology.]]

* LethallyStupid: The journalist tracks down Yuuma and confronts him for his curse. He demands that Yuuma give his side of the story, or he will out the guy and his sister. The two have no choice but to comply. [[spoiler: This leads to Yuuma taking responsibility for his actions... by apologizing on national television. You can guess what happens]]. Of course, it makes sense when you learn that [[spoiler:said journalist was actually the ''Devil'', wanting a public massacre].

* KillEmAll:

* ParanoiaFuel: [[invoked]] Invoked and clearly spelled out by the "curtain-call" epilogue, which makes it clear that the apologetic type is to be seen as a source of fear.

* VillainousCrush: Chizumi develops a crush on a young boy named Tomohito in one chapter. While having Chizumi as an admirer is as mentally-scarring as you'd expect, her feelings ''do'' appear to be genuine, to the point where she makes a point of stopping Yuuma from apologizing to him so that he won't die.

* MistakenForDisease: As time goes on, characters around Yuuma to suffer chronic runny noses and advancing disorientation, initially believed to be caused by a cold or flu infection. It's actually a side-effect of hearing Yuuma's obsessive apologies. For good measure, they're wrong about the symptoms as well: the victims' brains are ''beginning to melt and pour out of their nostrils.''

[[caption-width-right:300:Gonna need a mop for this one.]]

* CantStandThemCantLiveWithoutThem: Yuuma is constantly exasperated by Chizumi's meddling, and, by the later chapters, openly calls her a monster. Despite this, he goes out of his way to take her with him whenever he's forced to go on the run, and seems to hold himself responsible for her situation to a certain degree. Of course, if we're to believe both Chizumi's claims that Yuuma is a devil worshiper and Yuuma's claims that Chizumi is the devil's spawn, there might be more to it than simply brotherly attachment.

* CantStandEmCantLiveWithoutEm: Yuuma is constantly exasperated by Chizumi's meddling, and, by the later chapters, openly calls her a monster. Despite this, he goes out of his way to take her with him whenever he's forced to go on the run, and seems to hold himself responsible for her situation to a certain degree. Of course, if we're to believe both Chizumi's claims that Yuuma is a devil worshiper and Yuuma's claims that Chizumi is the devil's spawn, there might be more to it than simply brotherly attachment.

* MaskOfSanity / TheyLookJustLikeEveryoneElse: Yuuma is much more normal-looking, polite and seemingly kind than his sister is, but he may in fact be much, much worse than her. It's even suggested at a few points that Yuuma is the reason ''why'' Chizumi is as insane and corrupt as she is.