Blood Lad Omnibus, Vol. 1 (Blood Lad Omnibus #1) by Yuuki Kodama (Creator)
The vampire Staz is one of the most powerful district bosses in the demon world, fending off everyone who dares challenge him. But secretly, the fearsome Staz is obsessed with human culture, especially video games, manga, and everything that comes from Japan! When a Japanese girl wanders into the demon world, Staz can’t wait to meet the human and learn everything he can about her world. Unfortunately, before he’s able to ask her anything, the girl is killed by one of his would-be usurpers, leaving just her bare soul behind. Staz vows to help the girl restore her body and return to her former life-especially since it means taking a trip to the human world himself! Summary from Goodreads.