Juujika no Majutsushi

From MangaHelpers: Amano Haruhiko is a highly skilled exorcist and was a member of the Russian exorcist group, "Icon." Now he lives in Hokkaido and is in charge of a small and not particularly successful church. With him is Sister Amelia, who is constantly chiding him about his unseemly attraction to money. However, he still does his work as an exorcist, whenever he is asked. The story begins with a request from a Catholic girl's school headmistress, who is concerned about a monster plaguing her school. [tethysdust]