"Ah! My Goddess", created by Fujishima Kosuke, is a story about a vertically impaired college student who tries to order a pizza. Instead of getting pizza, though, Morisato Keiichi accidentally dials a wrong number and gets the Relief Goddess Office instead. A goddess named Belldandy pops through his mirror and tells him that she is there to grant his wish.

Keiichi doesn't really know what to do, and so he wishes for a girlfriend just like Belldandy. Belldandy interprets his wish a little differently than he'd intended her to, and becomes his girlfriend. Because Keiichi lives in a "guys only" dorm, his senpai throws him out when he gets home. Keiichi and Belldandy end up living in an abandoned temple, which Belldandy restores using her powers. Later on in the series, Belldandy's two sisters (Urd and Skuld) join them.

Belldandy is a Goddess First Class, Second Category, Unlimited. Her domain is the Present. She likes Darjeeling tea. Belldandy is a kind goddess who is very empathetic and gets along with almost everyone. She is more likely to cry than to hurt anything, which isn't necessarily a bad thing. She possesses awesome power, and if she were to use it to hurt something...let's just say that it would stay dead, if only for fear of being attacked again. Mostly she uses her power to heal things, or fix things, or make things pretty. She loves her sisters and Keiichi very much.

Urd is a Goddess Second Class. Her domain is the Past, and she enjoys "playing Cupid". She is responsible for running the Yggdrasil computer system, and she is Belldandy's older sister. She causes trouble frequently, though most of the time her intentions are good.

Skuld is also a Goddess Second Class. Her domain is the Future. She really likes fixing and building things, even though some of her inventions don't quite turn out right. Skuld is in charge of debugging Yggdrasil, a duty that is performed by smashing with a hammer creatures which look like crosses between rabbits and spiders. Skuld is not too fond of Urd and Keiichi. She thinks that Keiichi is trying to "steal" Belldandy, her favorite sister. As for Urd...well...those two just don't get along.