3,700 Years ago, the King of Demons fell due to love. The battle for the throne in the demon world intensified. In order to protect the demon king, the four guardians used the power of gods to extradite their clans to the human world and sealed the passage between the human world and the demon world. 3,700 Years later, the barrier between the human world and the demon world is gradually fading. Monsters with low cultivation levels that are not restricted by the seal began to break into the human world to cause destruction, trying to force the protectors to hand over the spirit consciousness of the demon king.
The Joint Investigation Bureau, an agency set up by a monster to help humans solve supernatural incidents, came into being. Our heroine gradually learned the truth about the demon king's fall while constantly taking on tasks from the Investigation Bureau, as well as her constant entanglement with herself. When the hope of the entire clan lies with a little fox demon who just wants to live a carefree life like a human being, where should she go?