Devilish Demons

Has anyone every wondered why exorcists never mention Lucifer or Devils? Well, they do exist. So, meet Ryuu Hamato, only son of the late Lucifer and the only half Devil in existence. He tags along with Rin, Yukio, and the others for the rid of his life as he works to become an exorcist. But, there's a certain Demon that get's in his way along the ride.(YAOI, don't like, don't read)