History Fridge / AssassinationClassroom

** Itona Horibe [[spoiler:and Akari Yukimira]] desired strength and both went crazy with their new powers as a result of the tentacles absorbing a ton of energy from the brain in order to grant them this power. If Koro-sensei asked for the same thing, he would have been an insane monster hellbent on killing everyone in the planet.

* Yanagisawa/Shiro has repeatedly declared his intention to give Koro-sensei "the cruelest death imaginable." In Chapter 170, [[spoiler: he and the second God of Death show up, interrupting a heartwarming moment between Koro-sensei and his students and revealing that "Number 2" has been transformed into another tentacle monster. Past assassins, including Number 2, have noted that using Koro-sensei's concern for his students against him is an extremely effective tactic. Now, under those circumstances, what could possibly be the cruelest thing to do to Koro-sensei...?]]

* Yanagisawa/Shiro has repeatedly declared his intention to give Koro-sensei "the cruelest death imaginable." In Chapter 170, [[spoiler he and the second God of Death show up, interrupting a heartwarming moment between Koro-sensei and his students and revealing that "Number 2" has been transformed into another tentacle monster. Past assassins, including Number 2, have noted that using Koro-sensei's concern for his students against him is an extremely effective tactic. Now, under those circumstances, what could possibly be the cruelest thing to do to Koro-sensei...?]]

** And it seems like [[spoiler:the second Reaper]] has become just that as of [[spoiler:Chapter 157]].

* Back on the page for UsefulNotes/The47Ronin, it mentions that a lot of the characters in ''Assassination Classroom'' are named after them, with Koro-sensei being an analogue to Kira. the oft mentioned question of [[spoiler: the possibility of Kira dying of natural causes before the actual assassination happens]] is finally given an analogue as through the simple fact that [[spoiler: Koro-senei could [[SecretlyDying eventually meet his end in such a fashion]] if the students don't kill him themselves by March, with the rest of the world hanging in the balance as well]].

** Itona Horibe [[spoiler:and Akari Yukimira]] desired strength and both went crazy with their new powers as a result of the tentacles absorbing a ton of energy from the brain in order to grant them this power. If Koro-sensei asked for the same thing, he would have been an insane monster hellbent on killing everyone in the planet.

* Koro-sensei's backstory reveals he asked to be ''weak'' during his [[spoiler: transformation]]. This guy who can go Mach 20 and is nigh unkillable is ''weak''. The amount of power one might have if they went through the same process and asked for strength is horrifying with that in mind.

*** [[spoiler:...or sacrifice herself in order to kill Koro-sensei.]]

* The Chapter 125 Colour Page has Kayano and Koro-sensei on it for Valentine's Day, both of them thinking about the same type of candy in the snow, and a Valentine's candy box with "Got to '''kill''' soon" written on it, with the "kill" written over "meet". Then along came chapter 128: [[spoiler:[[WhamEpisode Kayano has tentacles, is in love with Koro-Sensei, and wants to kill him.]]]] In hindsight, it was like a knife to the reader's throat and we never caught on until TheReveal blew it wide open, like a true assassination - we never saw it coming until it already occurred.

** [[spoiler: Nah, Kayano won't surrender quietly, it's more likely she'd be forced to reveal identity and defeat Takaoka at that.]]

* Back on the page for UsefulNotes/The47Ronin, it mentions that a lot of the characters in ''Assassination Classroom'' are named after them, with Koro-sensei being an analogue to Kira. the oft mentioned question of [[spoiler: the possibility of Kira dying of natural causes before the actual assassination happens]] is finally given an analogue as well through the simple fact that [[spoiler: Koro-senei could [[SecretlyDying eventually meet his end in such a fashion]] if the students don't kill him themselves by March, with the rest of the world hanging in the balance as well]].

** [[spoiler: Nah, Kayano won't surrender quietly, it's more likely she'll be forced to reveal identity and defeat Takaoka at that.]]

** [[spoiler: Nah, Kayano won't surrender quietly, it's more likely she'll be forced to reveal identity and defeat Kataoka at that.]]

** With the reveal in Chapter 128, it can also be inferred that [[spoiler:The pool of anti-sensei material would have also killed Kayano anyways. Korosensei would have been in a situation where there was likely no chance to save Kayano, so he would have died knowing one of his students would have died with him.]]

* In chapter 133, Korosensei starts revealing his back-story by stating that [[spoiler:he was once an assassin known as the "God of Death" two years ago.]] All of a sudden, all of the advice he gives and all of the lessons he taught to his students about assassination makes sense - [[spoiler:he was once [[WorldsStrongestMan THE Best Assassin In the World.]]]]

** To top it off, Nagisa [[spoiler: would never learn that the virus was a fake and his friends were never in any real danger. He would've died [[DespairEventHorizon thinking that his classmates were doomed to a slow, agonizing death]]]]. That would've been one HELL of a DownerEnding for this arc, if not for the entire series.

** '''Weakness 29: He gets carried away by official positions''', where he took his role as the jailer during the Cops and Robbers game way too seriously. Earlier, Koro-sensei also played the role of a hot-blooded baseball coach and an overly strict lifeguard ('''Weakness 22: He’s very strict about poolside manner''') to the same degree. But what's Koro-sensei's official job, you know, the one that he's ''really'' good at and the primary motivation behind playing all of the above positions so well? [[Heartwarming/AnsatsuKyoushitsu Being Class-E's homeroom teacher]].