Welcome to the future of vast bio-constructed cities with crime so severe that the cops drive tanks! For top tank-cop Leona Ozaki (and her trusty tank, Bonaparte), the day-to-day is a tall order already, but when the villainous and sexy (and super-powered androids!) Puma sisters become duly deputized officers of the law and are assigned to "help" Leona catch Urushi-Maru, "The Skyscraper Pirate," things are bound to get out of hand, especially in the midst of a full-on, tank-on-tank streetfight between Leona and a corrupt arms manufacturer bent on getting the city's police tank contract!.