Hailing from Datania, a nation infamous for exploiting underage labor, Shu and his comrades made a bid to escape their place of birth. Their journey brought them face-to-face with the Returners: a band of insurgents striving to topple Datania's tyrannical regime. Upon enlisting in their struggle, Shu was drawn into a conflict against Zero, Nines, and their accomplices' scheme to exploit DT, a scarce element contained within people, for their sinister designs.