The story is based on the manga Goyokiba, by Kazuo Koike and features an incorruptible police man in feudal Japan with unusual methods
In this particular movie, Hanzo and his assistants, Devil-Fire and Viper initially argue with Okubo, the government treasurer and his bodyguard Mikoshi. Later on, they discover a dead body of a young woman that leads them to an underground abortion sect, headed by priestess Nyokai, in a case that ends up being a lot more complicated than Hanzo originally thought.
The rest of the movie is an intermixture