A certain samurai lord has given away his newborn son’s organs to forty-eight demons in exchange for strength in battle. However, the child he abandons manages to survive after a medicine man finds him and gives him a set of lethal prosthetics. The child, Hyakkimaru, will use these prosthetics to find the father who abandoned him, as well as the multitude of demons that have helped themselves to his organs all in a bid to reclaim his body one part at a time. At such a time will Hyakkimaru go on to confront his father; however, while on his journey to find his organs, he encounters a certain orphan who claims to be the greatest thief in Japan.

Seth is an aspiring sorcerer from the Pompo Hills area and like all wizards, he’s an “Infected”, one of the few people to survive the contact of the “Nemesis”, creatures from the sky that destroy and contaminate everything they touch. Seth is immune to the Nemesis and wishes to become a Hunter in order to combat them; however, he wants to do more than just fight the Nemesis – he wants to find the Radiant, their cradle. With the help of fellow sorcerers, Seth travels the world looking for the Radiant.