Sumire, a nine-year-old girl with clairvoyant abilities, is held captive aboard a train by Doress, a secret organization that is transporting her to their laboratory. Spotting an opportunity to escape, Sumire accidentally releases Doress' top secret experiment: Ikurou Hashizawa, a 17-year-old boy infected with the Baoh parasite. Possessing extraordinary powers of invulnerability and regeneration, Ikurou helps Sumire, and the two flee together. However, this is only the beginning of their troubles. Because Ikurou's development is incomplete, Doress deems him far too dangerous to be at large and orders his immediate execution. Now on the run, the pair must survive an onslaught of hitmen while Ikurou tries to understand his rapidly advancing powers.