Kamisama Onegai!

Every night, Akumu is plagued by dirty dreams. Determined to escape from them, he enters a school called St. Noel Gakuen, which is run by a handsome priest. Here Akumu meets the gorgeous Yagiri and promptly begins to dream about him, much to their mutual embarrassment. It turns out that Akumu is a succubus who's leaching the life from Yagiri, who turns out to be a vampire. But that's okay! Since the priest who runs the school is god who has the power to save them both - if they can stay on his good side!