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.

Imagine a world where advanced science and sorcery coexist. Unfortunately, where there is great power to do good, there is even greater risk, and the use of magic comes at terrible cost: Magic use turns humans into bloodthirsty, destructive demons. To safeguard against this eventuality, magic users wear special armor—armor which sometimes fails. Society's last resort should a magic user's armor fail are the, government-employed tactical sorcerists, colloquially called “Strait Jackets.” Lately, there has been a disastrous uptick in the number of demon attacks, forcing the Sorcery Management Bureau to call upon assistance of the rogue Strait Jacket Leiot Steinberg and the mysterious child that accompanies him. Can Leiot stop the demons and figure out what is causing the outbreak? Or will he just end up a demon himself?