The movie opens with a court sanctioned duel to settle a dispute between two samurai. A bamboo enclosure is built for the occasion. The clan leaders are excited to host the duel, thinking it will bring honor on to thme if they run it correctly. The movie then uses flashbacks to show the events leading up to the duel intertwined with scenes preparing the "stage" for the duel.
The duel came about because of a comment that a passing noble samurai made about a spear of a poorer samurai, Shinpachi, not being polished. It evolved in to a matter of honor. A challenge to a private duel (which were forbidden by the clan) was issued, and the wealthy clan heir was slain.
The slain man's brother, Shume now wants revenge. When an investigation takes place, and the minister decides to declare both of the duelers insane, so that Shume can honorably take over his clan, and Shinpachi's life can be spared. No sense in disturbing things any further. But Shinpachi is banished from the village, and goes to a mountain monastery. He is hoping to wait a period of time until everything is forgotten, and he can return to his village.
But Shume, who has won his inheritance, is now worried that people think he is more worried about material things, rather than honor. He decides he must kill Shinpachi to restore his honor. He decides not to duel, which is forbidden. He is going to just kill Shinpachi. In the fight that ensues, Shume is clearly the better swordsman, but gets killed when his sword hits a branch.
now the clans have a real dilemma. Two noble samurai slain by a "madman". The clan of the slain brothers now submit a petition for a revenge duel. The fief advisers decide that the best course is to let the clan have the best revenge possible, so this affair will just go away. When Shinpachi's brother, and even his mother, tell him that for the good of the clan, he must lose the duel, Shinpachi is devastated.
But Shinpachi is willing to accept his fate. He is willing to let the youngest brother of the two samurai he has slain, Tatsunosuke, kill him in the duel. If he changes his mind he is to be ambushed by six samurai who will then disable him for Tatsunosuke.
When the duel comes, the crowd turns on Shinpachi calling him a murderer and a villain and throw rocks at him. The formal ceremonies of the duel are then held. Shinpachi and Tatsunosuke eat and drink. Then the duel begins the six assistants eun out with their swords drawn. Shinpachi who had not planned to fight, now takes on the six before a stunned crowd. When two are killed more skilled samurais are ordered on to the field and Shinpachi is finally struck down to the shame of all who took place in this travesty.
The movie points out that the formalities and conventions of the samurai society were considered more important than the individuals living in that world. Regardless of the consequences to individuals, the show must go on. Directot Tadashi Imai criticizes the samurai system without glorifying its violence, which is really different from most chanbara movies. A wonderful, very much underrated film.