Koro-sensei is a teacher for class 3-E of Kunugigaoka Junior High School and the main antihero of Ansatsu Kyoushitsu. He was responsible for carving out a large chunk of the moon to become a permanent crescent moon and plans to destroy the earth after teaching class 3-E for a year. - Wallpaper Abyss At Koro-Sensei's stage, it might not even be possible, but unfortunately, due to Koro-Sensei's death, fans will never know for sure. 55 Koro-sensei HD Wallpapers and Background Images. Download for free on all your devices - Computer, Smartphone, or Tablet. 7 He Never Got Another Shot At Love During their field trip to Kyoto, the girls of Class 3-E deduced that Koro-Sensei must've had some type of romance in the past, given his infatuation with the female body.