Made during the height of the Cold War, the film follows the lives of spies caught up in the power struggles of their times.
Years of warfare end in a Japan unified under the Tokugawa shogunate, but the peace is threatened.
When a high-ranking spy named Tatewaki Koriyama defects from the shogun to a rival clan, Sasuke is caught between two rival groups of spies, those working for the Tokugawa Shogunate and those supporting the Toyotomi Clan.
The Tokugawa spies are led by Sakon Takatani (Tetsurō Tamba) and Tatewaki Koriyama (Eiji Okada) and the Toyotomi by Shigeyuki Koremura (Eitaro Ozawa) and his lieutenant Takanosuke Nojiri (Kei Satō).
He escapes but soon meets the beautiful woman who entices him to come to her room, and when she turns up dead Sasuke is suspected.