History YMMV / DissolvingClassroom

* NarmCharm: The fact that Yuuma is apparently a worshipper of Satan himself, who is the source of his ability to cause people's brains, then the rest of their body to horribly dissolve into a goo, and whom the latter of makes an appearance in the final chapter manages to be extremely scary, thanks to Creator/JunjiIto being his ever-reliable self as always and illustrating people dissolving and the devil himself in the most horrifying fashion possible.

* TheWoobie: Yuuma, if you believe him to be genuinely innocent. He has been cursed with the power to melt everyone he either apologizes to or compliments and has no control over it whatsoever. To make matters worse, his younger sister has been driven insane by the trauma that she's experienced and now goes out of her way to trick other people into thinking that he's a heartless sociopath who enjoys what he does. He has to live his life constantly moving from one place to the next, always with the knowledge that everyone he meets will die horribly.

* NauseaFuel: Considering every chapter builds up to every character besides the main two meltings into puddles of human remains, this is to be expected.

* MoralEventHorizon: The series is ambiguous about if Yuuma or Chizumi is telling the truth about which is truly the evil one. There is one moment, however, where they actually team up and cross the line: Chizumi falls for a local boy, and her idea of courtship is to leap on him and lick his skin. When Yuuma sees it, he lies to the kid that he can hide at the house, only to reveal that Chizumi is his sister. They proceed to tie him up and lock him in a cell so that Chizumi can continue to "play" with him, where they store the bottles containing essence of the people he previously melted. Note that Yuuma never opens his mouth and apologizes to the boy, for fear of melting his body. The implication is that he ''can'' control that power and is doing so for Chizumi's sake since she likes the kid. [[spoiler:Much to the reader's surprise, the boy escapes thanks to the people in the bottles knocking themselves over, spilling over him, and ordering him to use the grease to wiggle out of his bonds. He runs for it and goes to the cops. Then he finds out that Yuuma and Chizumi already got rid of his parents, to avoid any unnecessary witnesses]].

** Chizumi. She apparently UsedToBeASweetKid, but was turned into a monstrous CreepyChild as a result of either becoming fully possessed by the devil or simply going insane from watching her brother kill so many people. [[spoiler:Her and Yuuma dying in the end seems to be a relief to her]].
** Yuuma is a more mild example if you interpret him as a devil worshiper. His parents were extremely strict and abusive towards him, which eventually pushed him to seeking out the devil for comfort. Not exactly the strongest FreudianExcuse relative to his actions, but still quite tragic.

* {{Anvilicious}}: The epilogue features Yuuma's [[AnimatedActors 'actor']] talking about how apologies attract everyone's attention, and hints at the moral that it is possible to apologise too much.

* DracoInLeatherPants: Yuuma attracts a lot of this attention in-universe from people who are convinced that no one as seemingly kind as him could be a bad person. This sympathy frequently carries over to Chizumi, who they believe was simply twisted by a bad environment. Of course, this is all assuming that Yuuma actually ''is'' the person that Chizumi claims him to be.

** Chizumi. She apparently UsedToBeASweetKid, but was turned into a monstrous CreepyChild as a result of either becoming fully possessed by the devil or simply going insane from watching her brother kill so many people.

* NauseaFuel: Considering every chapter builds up to every character besides the main two melting into puddles of human remains, this is to be expected.

* BigLippedAlligatorMoment: The entire second chapter. While the rest of the story focuses solely on Yuuma's status as a literal ApologeticAttacker, this one instead introduces his ability to disfigure women by complimenting their beauty, something that never comes up ever again.

* {{Anvilicious}}: The epilogue mentioned above features Yuuma's 'actor' talking about how apologies attract everyone's attention, and hints at the moral that it is possible to apologise too much.

* BigLippedAligatorMoment: The entire second chapter. While the rest of the story focuses solely on Yuuma's status as a literal ApologeticAttacker, this one instead introduces his ability to disfigure women by complimenting their beauty, something that never comes up ever again.

** Is Chizumi a young girl who went insane after witnessing the deaths of her parents and the grotesque supernatural events that her brothers causes, or is she completely possessed by an otherworldly force? Does she lie about Yuuma being a devil worshiper in order to torment both him and those who he grows close to? Or is she attempting to warn others to avoid associating with her brother?

** Is Chizumi a young girl who went insane after the deaths of her parents, or is she possessed by an otherworldly force? Does she lie about Yuuma being a devil worshiper in order to torment both him and those who he grows close to? Or is she attempting to warn others to avoid associating with her brother?

** Chizumi. She apparently UsedToBeASweetKid, but was turned into a monstrous CreepyChild as a result of either becoming possessed by the devil or simply going insane from watching her brother kill so many people.