In a declining future world, survivors excavate resources from ruins, and a new profession has emerged: Airship Knight. The blonde Airship Knight Dorota navigates this wasteland by air — until she discovers an amnesiac girl named Agate among the ruins. Agate comes from a civilization long believed extinct, and her appearance is somehow connected to robots that have suddenly begun to reactivate. Sky pirates take notice. Fellow knights Rita, Red, and Bell arrive to help as things escalate.