The plot of the manga is set in the future on a highly polluted Earth. Due to unbearable air quality, the people who inhabit the metropolis of New Port City are forced to wear oxygen masks when outside. Bandit accompanied by twins called the "Puma Sisters," tries to capture a top-secret government project that applies a plant's biology to a human's genome allowing for self-oxygenation. In doing so he hopes to prevent the establishment from forcibly changing the human race instead of solving the pollution issue. Captain Brenten and his squadron of Tank Police, composed of officers including Leona Ozaki among others, set out to put a stop to crime using their brute military force.
