After thousands of years of precipitation, demons and ghosts have stabilized in modern society.
The other world and modern human society have signed a non-aggression treaty. Demons and monsters have drawn a boundary in time. This boundary is managed by human monastic families, and each family has a key. The most important of these keys is in the hands of the Ji family, which has been passed down for thousands of years. However, a demon riot hundreds of years ago caused damage to the human monastic family. The border protection between the two worlds is crumbling. In recent years, abnormal accidents have occurred frequently in the human world. More and more demons are rioting.
Concept: In the modern era of scientific civilization, where will the legendary monsters go?