After losing his parents, our protagonist, Yuno, lives an unfortunate life as a servant in his stepmother's household.
One day, a series of natural disasters leads to him being offered as a human sacrifice to a family of gods.

The Ciel family, a family of gods, governs the heavens and the earth and is feared for their immense power. To avoid excessive human contact, they live in a remote castle towering deep in the mountains.
Yuno becomes anxious when she hears rumors that he is an exceptionally virile man and that women are only used as a source of his power. However,
upon actually meeting the head of the family, Jupiter, she finds him to be extremely responsible and kind.

Jupiter's unfulfilled sexual desires cause natural disasters, weakening his ability to repel demons, so Yuno becomes intertwined with Jupiter as a human sacrifice. Jupiter is
in a similar situation, alone and without family, and Yuno is gradually drawn to his clumsy kindness.

The demon he has been suppressing appears, threatening the two.
What will become of their love?
Will the world be saved?