Welcome to the future, where the norms are vast bio-constructed cities, air is toxic enough to force citizens to wear oxygen masks and crime is so severe that the cops drive tanks! When a mysterious winged girl with the power to cleanse the poisoned air is kidnapped by the villainous Buaku, police mini-tank commander Leona Ozaki, her tank Bonaparte and her lovesick partner Al must confront the arch-criminal and his catgirl molls - the beautiful and deadly Annapuma and Unipuma - before Buaku's master plan kicks into gear.