It is a world where magic and science coexist. Rayotte Steinberg, a lone wolf "tactical sorcerist", fights against monsters. They used to be human beings, but they have overused forbidden power, magic, to turn into monsters. What he wears is "mold", the straitjacket that keeps him human. He carries an explosive magic wand. If he casts magic, he moves one step closer to being a monster. If he doesn't, he will be killed. Among the harsh battles, he will face a sin he committed in the past.