Keiichi Morisato, a college student, mistakenly dials the Goddess Hotline instead of the food ordering number from his dormitory. This results in the appearance of a stunning goddess named Belldandy from a mirror in front of him. As a consequence of being expelled from the dorm, Keiichi relocates with Belldandy to an ancient shrine, where her sisters Urd and Skuld eventually join them.