In 19th century Japan, Hachiro (Tetsuro Tamba), a farmer trained in the ways of the samurai, supports the emperor as the besieged ruler is fighting off factions of feudal generals looking to seize control of the country. When Hachiro is captured by the generals, he is offered his freedom in exchange for executing a group loyal to the emperor. Although Hachiro accepts the mission, his motives are suspect to the army men -- and it remains murky which side this lone hero is really on.