College freshman Morisato Keiichi gets more than he bargained for wen he goes dialing for dinner and gets an unexpected delivery - Belldandy, a real live, honest to goodness GODDESS! Belldandy grants him a wish, and Keiichi decides that what he really needs is a girlfriend just like her. And that's exactly what he gets. The mysterious Ultimate Force that enforces all Wish Contracts comes into play, and Keiichi and Belldandy are now inseparable. Then Keiichi remembers that his dorm has a strict rule: NO WOMEN ALLOWED!

Five months have passed since Morisato Keiichi dialed out for dinner and got a goddess instead, but he still hasn't managed to put the moves on the divine Belldandy. Belldandy's big sister Urd is not amused, and decides to give him some serious make-out advice. The result is a trip to the seashore, where every attempt by Keiichi to advance a base or two with Belldandy goes hilariously askew. Then Urd unleashes her ultimate weapon - the Love Potion!

It's really lonely up in the heavens without your big sisters to keep you company, especially when that means you are stuck with the job of tracking down all the bugs that keep cropping up in the Ultimate Force System. So little Skuld decides to pay her big sister Belldandy a visit. When she hears about the contract that binds Belldandy and Keiichi together, she decides that something must be done!

Keiichi's life finally seems to be getting back to normal (or at least as normal as life gets when you live in a temple with 3 goddesses!). Yes, he does get strange dreams, and yes, Urd and Skuld are a pain, but what the heck - his girlfriend is truly divine! Alas, System Bugs are escaping from the Heavens, upsetting the balance of the Earthly Plane.

You'd think with a goddess as a girlfriend, Keiichi's life would be Heaven, but the fact is, it's coming to resemble the other after-life address. If he even gets close to Belldandy, Bugs escape onto the Earthly Plane and foul up the works. Worse, the Lord has slapped her with a Recall Notice.