Yomawari Meguru was summoned to defeat the Maou. After struggling all the way to where the Maou is and finished the job, Yomawari Meguru was betrayed. Being chased by the ones that he protected, casually betrayed by his comrades, he was forced to flee. But he met the Maou that should’ve been defeated by him, Pearlnight. And then, he swore. To make an enemy out of this whole world. The strongest Human and the strongest Demon. They’re going to punish the comrades by whom they were betrayed.