Mika Katagiri wants her band to perform at the upcoming local festival. However, complications arise. Their keyboardist, Jun, refuses to play, and their stage has been cancelled. Refusing to give up, Mika and her band strive to find a way to play at the festival, using any means necessary.

The killer class is back in session—sort of. Relive every moment through the eyes of the top two students: Nagisa and Karma!

United by a common mission to eliminate their teacher, Koro-sensei, an alien creature with phenomenal strength, join Nagisa and his Class 3-E classmates in brand-new adventures.

A spin-off from Assassination Classroom, in this world, Koro-Sensei is the Demon King while the students of class 3-E are cast as heroes who must defeat him. The students learn swordsmanship and sorcery at Kunugigaoka Magic School. Their strange adventure begins!