A mysterious creature destroys 70% of the moon. The creature then warns that if he isn’t destroyed by March of subsequent 12 months, Earth can be subsequent. The creature additionally calls for that he turns into the homeroom trainer for third grade E class at Kunugigaoka Junior Excessive College. The federal government is powerless to say no. The creature then turns into the homeroom trainer of third grade E class which consists of failed college students together with Nagisa Shiota (Ryosuke Yamada). The creature is named Trainer Koro. In the meantime, the federal government requests that the scholars attempt to kill Trainer Koro though he possesses tremendous powers. The federal government affords a 10 billion yen reward for whomever efficiently kills him. The scholars are confused by the state of affairs, however resolve to kill Trainer Koro. When their class begins with Trainer Koro, the scholars finds themselves having a great time with their new trainer.