In a certain country in the demon world, the demon king is defeated by a courageous human. Vamirio is one of the Four Heavenly Kings and is in charge of the competition to determine the new demon king. Human beings are their enemy, and she is furious that the valiant Helck is joining. Before the final battle, she learns that Demon King Urum’s castle has fallen to the enemy. Together with Helck and the other competitors who made it to the final, she heads off to recapture Urum Castle. With a smile, Helck suggests, “Let’s destroy the humans.” Does he really mean it? What is he hiding behind his smile?