Rinami Kudo

When a massive, gilled monster emerges from the deep and tears through the city, the government scrambles to save its citizens. A rag-tag team of volunteers cuts through a web of red tape to uncover the monster's weakness and its mysterious ties to a foreign superpower. But time is not on their side - the greatest catastrophe to ever befall the world is about to evolve right before their very eyes.

A mysterious creature destroys part of the moon and then warns that if it is not destroyed before March of the following year, Earth will be next. It also demands to become the homeroom teacher of Class E, a third-year class at Kunugigaoka High School. As the deadline for the assassination and the date of the end of the world approach, the students discover their true abilities and Koro-sensei's shocking identity.