I am Korosensei, the teacher of Class 3-E at Kunugigaoka Junior Highschool, the “End Class”. I am the one responsible for blowing up the moon, and I will do the same to Earth if my students don’t menage to kill me at the end of the year! I didn’t always look like a 3m tall yellow octopus. Before becoming a teacher, I was also an assassin known as the “Reaper”, but everything changed after I met a very special woman named Aguri, who unfortunately she died in a very tragic way.