Innocent Bird(2002)

Na mo Naki Tori no Tobu Yoake

Part of the angelic bureaucracy, Karasu is sent to earth to retrieve a demon living among humans. However, he's surprised to discover that Shirasagi only wants to throw away his heritage and his powers, and live as a human, and a holy human at that. A priest working out of a bar in the city, Shirasagi teaches children and is generally an all-around wonderful person. But Heaven and Hell both want him back and it's going to be quite a battle.

(Source: BLU Manga)