Kazutora is a demon prince who has been quite bored in hell lately, so he decided to visit the human world.

Demons are not forbidden to walk in the human world, it's just a little dangerous, if they take on their human form there, they can stay there forever.

People can't see him if he doesn't want to, so he just flew around in the sky, but once he caught you. He started following. But bad faces stopped you and he found you interesting, so he took his human form and he came to protect you.