Genichiro Okugawa is appointed as the head of accounting in a feudal domain and travels with his servant Gonsuke to the country from Edo. Along the way, they are attacked by masked samurai on a mountain road. Genichiro is saved by Sukezaemon Tsuda, the supervisor of public works who was out hunting. Upon arriving in the domain, Genichiro is given a warm welcome by the vassals, who force him to drink heavily and find his subordinates to be rebellious. His proposed fiscal reforms are met with resistance, except by Tsuda who understands Genichiro's intentions. Genichiro marries Matsuo, the daughter of a senior councilor, but soon faces accusations of corruption.

Accused of being a spy for a rival clan by Nanbu Clan samurai who then attack him, the 'Lowly Ronin' barely escapes with his life after being shot. Nursed back to health by Yamaoka Daijiro, the one Nanbu Clan retainer that believes him, he must find a way to prove his inno-cence to the others. The two team up together to uncover the mystery and find out who the real spy is that threatens the security of the clan. Against all odds, the two master swordsmen must rely on all their skills to defeat a vast conspiracy and save the clan from being abolished.