When it involves the fantasy MMORPG Cross Reverie, none can match the facility of the Demon King Diablo. Possessing the game’s rarest artifacts and an unrivaled player level, he overpowers all foolish enough to confront him. But despite his fearsome reputation, Diablo’s true identity is Takuma Sakamoto, a shut-in gamer barren of any social skills. Defeating hopeless challengers day by day, Takuma cares about nothing else but his virtual life that is, until a summoning spell suddenly transports him to a different world where he has Diablo’s appearance!
In this new world resembling his favorite game, Takuma is greeted by the 2 girls who summoned him: Rem Galeu, a petite Pantherian adventurer, and Shera L. Greenwood, a busty Elf summoner. They perform an Enslavement Ritual in an effort to subjugate him, but the spell backfires and causes them to become his slaves instead. With things now becoming more awkward than ever, Takuma decides to accompany the women find how to unbind their contract while learning to adapt to his new existence because the menacing Demon King.