In Japan, there are demons who kill innocent people at night. Rui Kamishiro is one of these, but more often he killed and ate only those who disturbed him. He tried not to be seen by the hunters, but one time he was caught by the hunter Tsukasa and tried to hide, but he was wounded. When he was at a dead end, he tries to negotiate with him and even asks him to be at the same time with him, since Rui is indifferent to other demons. Demons can be killed by cutting off their heads or by sunlight.