Keiichi Morisato is an engineering student who has never had a relationship with a girl. A strange phone call changes his life. The minute he answers a call from the "Helping Goddess Office," the Goddess Belldandy appears before him. Belldandy offers to grant him one wish, and Keiichi asks her to stay with him forever. The wish is granted by the Gods, and Keiichi and Belldandy's strange yet loving life together begins. The consequences of the granted wish cause frequent trouble for the couple.