After losing her parents, Yuno is forced to live as a servant under his cruel stepmother. A string of natural disasters leads to him being offered as a human sacrifice to the powerful Ciel family of gods, who live in isolation deep in the mountains. Rumors say he is exceptionally virile and will be used to fuel their power, but upon meeting the head of the family, Jupiter, Yuno finds him kind yet burdened. Jupiter’s suppressed desires cause natural disasters and weaken his power to repel demons, making Yuno essential to his survival. As they grow closer through shared loneliness, a dangerous demon threatens both their bond and the world’s safety.