Tenmaru hails from the demon world as its prince, a royal status central to his origin. An accident under his command released 108 sealed monsters into the human world. To rectify this, he journeys from his realm to Earth, tasked with locating, recapturing, and returning every escaped entity to its original confinement. Accompanied by at least one ally, he pursues this mission across the human world, driven to resolve the chaos unleashed by the breach.