In a world where magic and science coexist, Rayotte Steinberg is a lone tactical sorcerer who battles monsters that were once human but have turned into creatures after overusing forbidden magic. To stay human, he wears a straight jacket called Mold and wields a staff that can unleash powerful explosions. Each time he casts magic he risks becoming a monster; if he fails to use his magic, he faces death. Amid these harsh battles, he must confront a sin he committed in the past.