The Earth's moon is suddenly 70% smaller and permanently crescent shaped by a devastating and unknown force. For the students of E Class, Kunugigaoka Junior High School, the being responsible is known, as their teacher. The strange and very supportive entity has given the Japanese government a challenge to save the Earth from destruction. It wants to be the teacher of the class with the lowest expectations for success, in anything. The students, armed with special weapons that only harm their teacher, must find a way to kill him before the end of the school year. If not, summer break will be canceled by the end of the world. Written by Titus O'Neill

Yuri Kashiwaga was once known as a genius pianist. One day, she returns to her hometown in Goto Islands from Tokyo. There, she begins to work as a temporary teacher at a middle school and advisor for the school chorus. The chorus aims to take part at a competition. Yuri gives the members of the chorus members an assignment. She instructs them to write a letter with the title of "To myself 15 years later." The 15-year-old boys and girls write about their secrets and worries.

A world wide electrical outage occurs. Everything that requires electricity comes to a stop. Tokyo is nearly ruined. Yoshiyuki Suzuki (Fumiyo Kohinata) decides to escape from Tokyo with his family.