A samurai lord has bartered away his newborn son's organs to forty-eight demons in exchange for dominance on the battlefield. Yet, the abandoned infant survives thanks to a medicine man who equips him with primitive prosthetics—lethal ones with which the wronged son will use to hunt down the multitude of demons to reclaim his body one piece at a time, before confronting his father. On his journeys the young hero encounters an orphan who claims to be the greatest thief in Japan.

Ji-Sook goes through a difficult period, due to her father's private loan. She begins living as Eun-Ha. Eun-Ha is from a wealthy family and looks like Ji-Sook. When Min-Woo was only seven years old, he became the successor of a large corporation which his family ran. Due to his position, he cannot reveal his feelings. Through his family, he meets Eun-Ha. He notices she is different from other wealthy woman that he has met. Min-Woo has feelings for her.

Brought together by a mysterious song, a grad student and an engineer lead the fight against an unimaginable force that may spell doom for the world.