A train crashes into the bus, killing everyone on board.
Haruto awakens in a dark room, now in the body of a malnourished boy, In the Kingdom of Beltrum year 991.
Confused and with mixed memories, he's no longer certain if he's still Haruto from Japan.
For he is now Rio, a poor boy living in the slums of the Kingdom of Beltran. Rio defeat a masked man, then he hears noises coming from a bag in the room. Inside, he finds a purple-haired girl. She asks him to take her to the Royal Castle, but she faints when she sees the unconscious masked man. Rio decides to take her to the castle, and his long journey begins from now on.