The deadline for assassinating Mr. Koro (voiced by Kazuya Ninomiya) is getting closer and closer, and the secret weapon that has been lurking in the third grade E class has finally been deployed. Kaede Kayano (played by Maika Yamamoto), who carries a great hatred, reveals her long-hidden tentacles and launches a desperate attack on Mr. Koro. It is precisely with the help of this incident that Mr. Koro tells about an unforgettable origin between himself and the former substitute teacher of Class E, Yukimura Aguri (played by Mirei Kiritani). Around whether the assassination operation will be carried out, Nagisa Shiota (played by Ryosuke Yamada), Akabane Karma (played by Masaki Suda) and others are divided into two factions. On the one hand, they hope to save the earth from destruction, and on the other hand, they try to save Mr. Koro's life. At the same time, the governments of various countries that have been silent for a long time have also begun to plan the final action, and Mr. Shiro (played by Hiroki Narimiya), who is the cause of all the chaos, will also become an important existence in determining Mr. Koro's fate. The moment of farewell between teachers and students will eventually come... This film is adapted from the super popular manga by Yusei Matsui.