On a thunderstorm night, a demon fox was born into the family of a pair of ordinary snow foxes. The fox father and mother were so frightened that they turned around and ran away; he was originally the son of the leader of the fox clan, but he was spurned by his clan members because of a mistake. When she grew up, she wanted to be an ordinary demon fox, but her wish was not fulfilled. A promise she made to him pulled her into a realm from which she could not withdraw. "What should I do if you leave?" What will the inadvertent dependence bring to these two lonely foxes? What does the sudden discovery of love mean between life and death, and what choice will they make...