Korosensei is shown as the homeroom teacher of Class 3-E of Kunugigaoka Junior High School, and the secondary protagonist and antihero of Assassination Classroom. He has the appearance of a yellow octopus. Korosensei claimed to be responsible for creating the permanent crescent moon and added that he planned to destroy the earth after teaching Class 3-E for a year. Prior to being a teacher, he was the assassin known as The Reaper in our fanart Assassination Classroom Korosensei Sticker.