Rio carries two dead lives, one in the slums, one in a car accident, and neither one stops chasing him. The show doesn't waste time philosophizing about it; it just builds a world where those two pasts collide and force him to move forward. By the finale, that connection to the world he died leaving behind becomes the whole reason anything matters.

Rio is an orphan fighting to survive in the slums after his mother was murdered when he was young. One day he wakes to the memories of Haruto Amakawa, a Japanese university student who died in a traffic accident, and realizes he has been reborn in a realm of swords and sorcery. As the two sets of memories merge, he finds he holds potent magical powers, and his drive to avenge his mother remains. When he stumbles on the kidnapping of a princess of the Bertram Kingdom and rescues her, the king rewards him with a place at the Bertram Royal Academy, a prestigious school for the children of nobles. Life there proves hard for a boy from the slums, and as he tries to rise from the bottom of a rigid social order, he meets new people, parts from others, and fights to overcome his fate.