Nine-year-old Sumire, gifted with clairvoyance, is abducted by the clandestine group Doress and taken captive on a train bound for their lab. In a twist of fate, Sumire inadvertently frees their secret weapon: Ikurou Hashizawa, a 17-year-old infected with the Baoh parasite, granting him incredible regenerative abilities. Together, they flee, only to face a new threat. Doress, fearing Ikurou's uncontrollable potential, orders his elimination. As they evade relentless assassins, Ikurou grapples with mastering his burgeoning powers while seeking answers to his mysterious origins.