Unfortunate accidents and strange occurrences are mostly devil's work. People might not realize this, but the world is full of devils. Professor Sakakibara and the devil Unknown solve cases between humans and devils using the Book of Sorcery.

Included one-shots:
* Furou Kyoudai Tokubetsu-hen

*Kaizoku-hime / Pirate Princess
Jill seeks freedom on the high seas! Jill wants to become a pirate!