During a period of strife, machines known as "clockworkers" were built to kill men. Possessing superior strength and near-impenetrable armor, these automatons far outmatch any human. However, although war is long over, clockworkers still cling to their one sole purpose: fighting. With such a resounding problem threatening the delicate peace, the Asteria Empire created the Clockworker Administration (CWA)—an organization utilizing repurposed clockworkers that now hunt their own rogue kind.

Journeying across the country is CWA member Machina, a hotheaded girl whose steadfast ideals may not be so different from her enemy. Alongside her trusty repurposed clockworker partner Deus, Machina swears to destroy every clockworker in the world by any means necessary.