Ryo Saeba works the streets of Tokyo as the City Hunter. He's a "sweeper" and with his sidekick Kaori Makimura, he keeps the city clean. People hire the City Hunter to solve their dangerous problems, which he does with a Colt Python. When Ryo's not working on a case, he's working on getting the ladies, and Kaori must keep him in check with her trusty 10 kg hammer.

Ace female test pilot Kusomoto Elle humiliates macho tank driver Lt. Kilgore in the first demonstration of the advanced personal battle tank, the MADOX. Kilgore vows revenge, and gets his chance when the army rather carelessly loses the prototype in Tokyo. The MADOX is found by engineering student Sujimoto Kouji, who doesn't take the time to completely read the manual and ends up zooming around Tokyo trapped in a machine he doesn't quite know how to operate. Guess who gets the job of stopping the now mobile missing MADOX? Poor Kouji. If he's late for his date, it's over between him and his girlfriend. His current attire redefines the term "over-dressed." And to top it all off, Kilgore wants to make him late- as in "the late Kouji!"