During the final battle between the Demon King and the heroes, a distortion of time and space caused by the clash of the two heroes' inner powers engulfs the Demon King's castle, and the two are transported to the middle of Toyosu, Tokyo, far away! The Demon King and the heroes try to return to their original world. But in Toyosu, where there is no magic in the air, they cannot even move to a neighboring town. Yua, the grandson of the landowner, who is angry at the appearance of the mysterious building, forces the Demon King to remove it immediately, and he proposes to run the castle as a 9-story condominium. But the Demon King is not satisfied with the plan, and says, "All the people living in this mansion! Why haven't you paid the rent? The residents gathered at the dubious property are all crooks that even the Demon King has trouble with! For the sake of the residents' prosperous lives (? The demon king's real estate comedy, in which he struggles to enrich the lives of the residents, opens in Toyosu!