AA! Megami Sama [OVA]
This story is about Morisato Keiichi, a college student in the Nekomi Institute of Technology (NIT for short), who accidently calls the Relief Goddess Office while ordering a takeout, and summons Belldandy. Belldandy grants him one wish and Keiichi, thinking that this was one of his Senpai’s practical jokes, wishes for a girl like her to stay with him forever. To Keiichi’s surprise, it was for real, and Belldandy has to stay with him forever. This gets Keiichi kicked out of the dorm, which doesn’t allow women. So, Keiichi and Belldandy goes off to search for a place to stay, and eventually end up in an old temple where they begin their new lives together.