"The goddess who promised to marry me when I was a child...!?"

In order to shorten the commuting time to school (five hours round trip!), which had been bothering him, the protagonist, Kotarou, ends up living in his grandparents' mansion.

What awaits him there is a girl named Lilium, who calls herself: "Your wife"

She is the girl Kotarou promised to marry when he was still a child. What's more, she's a goddess——!?

"From Good Mornings to Good Nights, please leave all of it to the Goddess♪"

[Edited from Official Website]