At Kunugigaoka Magical Academy, the underachieving students of End-Class find themselves assigned an unlikely new teacher: a smiling Demon King who wants them to master their hidden magic well enough to eventually kill him. Nagisa Shiota, Karma Akabane, and their classmates train under Koro-sensei while fending off rival magical factions and their own poor grades, playing the core cast's Assassination Classroom dynamic for fantasy-parody laughs. The spin-off swaps the original's tentacles and mach-speed movement for swords and spellcraft.