In a desolate future, Earth is barren and humanity has long vanished. The only survivors are robotic beings intended to be immortal, until Luna's demise triggered the Ruin - corroding their bodies beyond repair. With death's inevitability, the despairing robots cling to a myth that devouring Casshern will grant them everlasting life. Casshern is cognizant of nothing - ignorant of his origins, purpose or nature - but he must unravel his past, lest he suffers eternal persecution at the hands of machines fearful of expiration. Though he leaves a trail of destruction in his wake, Casshern must confront it to uncover the truth of this world.