One day, when trying to call a video store, he accidentally called the Goddess Helpline, which summoned Belldandy, a Heaven-born angel (called "goddess", even though she's an angel and not a goddess). Belldandy reveals that, since Keiichi has followed the path of the Almighty One (God), he is granted one wish from Belldandy. Keiichi, taken aback by Belldandy's gentle and kind nature, says "I wish for a goddess like you to stay by my side forever". Keiichi's wish is immediately granted, and from that point on, Belldandy lives alongside.
Keiichi quickly starts falling in love with Belldandy, and Belldandy feels the same way. They become boyfriend and girlfriend, and eventually they get married.
Keiichi is kind, gentle, friendly and humble. He is a car entuthiast and thus not only knows a lot about cars, but can fix or build cars from scratch. He is also very level-headed and often acts as the voice of reason among the household.