New-Port City has a problem with crime, and in order to combat it, the mayor orders the creation of a new police unit: the Tank Police! Trouble ensues when the feisty Leona Ozaki is transferred in from the motorcycle-division, and has a little problem getting used to the tanks — in particular how to drive them without demolishing buildings — and accidentally destroys the personal tank of the unit's commander, Lt. Brenten. Threatened with reassignment to child-welfare, Leona builds a new smaller tank out of spare parts, with the help of Al and the Chaplain. The new tank, christened Bonaparte by Leona, is finished just in time to stop crime lord Buaku and his henchwomen, Anna Puma and Yuni Puma (aka the Cat Sisters), from stealing urine from people who are unaffected by the poison cloud that hangs over the entire planet. Finally accepted into the Tank Police, Leona ends up causing as much, if not more, trouble than the rest of the team ever did.