The Assassination Classroom in class 3-E. Where students are trained to kill tragets also, In there, the moon has just gotten destroyed by something to 70%. Class 3-E has just gotten a new student and also with that, a new teacher along with that.

The new student are you, but strangely on the same day, that octupus alian thing came and explained; that he's gonna destroy the earth in one year exactly, if the class can't kill him until the then. So the class tryes their best to shoot him, stab him or kill him in any possible way, but with his speed of 20, it's almost impossible.

(Agust 27th)

The class has started, you as an new student has just gotten used to your classmates trying to kill the teacher, who they called "Koro-Sensei" since he actuly has no name.

Koro-Sensei isn't allowed to harm any student in order to be allowed to destroy the earth, he has to teach them and make sure they don't get hurt in any way. In all, he even gives most students some advices in how to kill him better, he knows it won't work.

(When the new teacher came)

there came a man, he wasn't the fittest with his looks and seemed to know Karasuma sensei. He told the students and Karasuma, that he'll be helping Karasuma in PE and train the students in combat too, but little did they know, that as soon as Karasuma sensei and Jelavic sensei took a look at some pictures of Akira Takaoka in the internet, they saw first a happy picture with him and the students from another class. But as soon as Karasuma sensei saw the backside of that picture, he was shocked. These students has cuts and bruises all over!

meanwhile with Akira Takaoka

Akira: "So class, you can see me as your new father figure, and I'll train you in combat!" he spoke with bad intentions

and the students didn't knew yet that he actuly wanted to hurt them, what Koro sensei won't let happen

(Koro-Sensei's emotions; Blue = Sadness. Red = Annoyance Black = Fury Pure White = Poker face, A mix of every emotion, or bored Mild-Yellow = Confused)