In a world where certain humans command mighty supernatural duos called Daemons, it is the birthright of "the children who sunder day and night"—twins Yuru and Asa—to rule over these powerful entities. Separated from a young age and unaware of the truth of their birth, brother and sister must fight to make their way back to each other, claim their birthright, and save the world...

Guided by Dera, Yuru flees from his pursuers and awakens the guardian deities of the village.

Yuru learns the truth about his village and learns the rules of modern society as he rides down the mountain.