Growing out of the chaos of a global war, the city of Utopia is populated by humans and bioroids (artificial humans). On the surface, everything is harmonious, but tensions lurk. Into this seemingly perfect society comes a survivor of the wars, Deunan Knute, who carries a legacy that will turn out to be of critical importance to the future of human

A promotional video for the manga. The story revolves around Gai, who was born beside a woman who met her death in a forest. He was adopted by the swordsmith Amon. A few years later, Gai becomes Amon's apprentice, and during the forging of a sword, he loses his right arm. To help him, Amon crushes the demon sword Shiryū (lit. Death Dragon) to form

Deunan, a young female warrior, and Briareos, a veteran cyborg-soldier, are both partners and lovers. As members of E.S.W.A.T., the elite special forces serving Olympus, they are deployed whenever trouble strikes. The two fighters find their partnership tested in a new way by the arrival of a new member to their ranks—an experimental Bioroid named

Death does not have to be the end; one can live again, but only through beating the game posed by the black ball called Gantz. On his way home to celebrate his younger brother's birthday, brave and kind-hearted student named Masaru Katou is stabbed to death. He awakes in a small room with a cityscape view in the heart of Tokyo—and he is not alone.