In the year 2050, Derrida Yvain, a young engineer, gained fame for his role in developing the "Autonomous Machine DZ" at Rebuild, his father's manufacturing company. Derrida and his colleague Nathan detected a flaw in the DZs and attempted to alert their boss, who disregarded their warnings. Knowing the perilous situation, they postponed taking action and instead attended Nathan's daughter Mage's birthday celebration. The following day, they were suddenly ambushed by an unknown assailant. During their escape, Derrida was placed in cryosleep and awoke 10 years later in the midst of a war-torn world. DZs run amok attacked Derrida, and he nearly gave up until he remembered Nathan's last words: "Take care of Mage." In the face of adversity, Derrida resolved to find Mage despite his bleak circumstances.