The two worlds of demons and demons were originally at odds with each other. However, at this time, the demon world with a clear class system began a new election for ten royal captains, and the ten selected ones can become members of the royal family. After a series of strict screenings, a new captain was born. After training, the new captain finally took over. But during the subsequent mission, it was discovered that there was a mole among the captain. Members of the demon world have invaded.