After a bus accident kills him in Tokyo, university student Haruto Amakawa's memories awaken inside Rio, a seven-year-old orphan surviving alone in the Beltram Kingdom's slums. The two consciousnesses merge, leaving Rio with both his own hardened survival instincts and Haruto's modern ethics, along with a newfound command of Spirit Arts. When Rio rescues the kidnapped Beltram princess without hesitation, the grateful king offers him a place at the Beltram Royal Academy, pulling him out of the slums and into the nobility's world.