A criminal syndicate wants detective Onihei dead, but the resolute hero proves to be hard to kill.

Takahagi Sutegoro is highly skilled at casing locations for thieves so that he can sell detailed floor plans to them. He suffers an injury to his leg while trying to help a parent and a child being threatened by samurai. Heizo jumps in and chases the samurai away. Feeling indebted to Heizo, Sutegoro decides to become his spy. Now, together they will try to stop scheming Myogi Danemon’s gang of merciless thieves...

Successful and married with children, paper-mill owner Jihei knows better than to contradict the strict social and moral codes of 18th-century Japan. But when he meets the lovely courtesan Koharu, he becomes a man obsessed. Koharu returns his love, even foregoing other customers while Jihei schemes to somehow buy her freedom. His efforts yield ruinous consequences for his business and his family life, and Koharu is meanwhile purchased by another client.