Three months after a hero slew the Demon King, humans rejoice in their victory while demons mourn their loss. A tournament commences to select the next Demon King. Vamirio, a member of the Four Heavenly Kings, presides over the event, her suspicion fixed on Helck—a human entrant who professes to despise his own species. Although she wishes to eliminate him from the competition, Helck's immense power and popularity make that difficult. As the tournament progresses, news arrives of humans disappearing from multiple towns. Determined to solve this mystery, Vamirio schemes to bring about Helck's defeat, hoping to expose his real motives and protect the demon realm from any looming danger.
