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.

Together with his partner Kaori Makimura, the kid sister of his late best friend, Ryo Saeba, fights the evil haunting the city.