Shuji Mimura works as a broadcast writer. He learns that he doesn't have much time left to live. He decides to concentrate on the future of his beloved family. Shuji Mimura's final plan is to find the best man to marry his wife Ayako.
Rena Misaki works at a bank. She lacks self-confidence. Because of a reason, she begins working for a PR company and her boss is Kusakabe. As she struggles to work under her new boss, Rena Misaki grows as a person.
A mysterious creature destroys 70% of the moon. The creature then warns that if he is not destroyed by March of next year, Earth will be next. The creature also demands that he becomes the homeroom teacher for 3rd grade E class at Kunugigaoka Junior High School. The government is powerless to say no. The creature then becomes the homeroom teacher of 3rd grade E class which consists of failed students including Nagisa Shiota (Ryosuke Yamada). The creature is called Teacher Koro. Meanwhile, the government requests that the students try to kill Teacher Koro even though he possesses super powers. The government offers a 10 billion yen reward for whomever successfully kills him. The students are confused by the situation, but decide to kill Teacher Koro. When their class begins with Teacher Koro, the students finds themselves having a good time with their new teacher.
Ninako Kinoshita has never been in love until an encounter with the school's most popular boy, Ren Ichinose, leads the two to befriending each other. Ren's patient and kind personality is a far cry from his unapproachable idol status at school, and soon Ninako falls in love with him. However, she must cope with the fact that he already has a long-time girlfriend.
