Soon after the last Demon King was defeated, the Demon Empire started a contest to choose the next Demon King. But the favourite contestant to win the tournament was no other than a human, The Hero Helck, whose motive to become the Demon King was to defeat his own race. What are Helck's true motives to participate in the contest and defeat the human kingdom? It's up to one of the Four Heavenly Kings of the Empire, Red Vamirio, to discover and unfold Helck's true intentions.