The movie opens with a samurai taking his short sword and stabbing a lady after a musical performance. We later find out in flashbacks that Sanzaemon, a low level samurai, assassinated his lord's cruel mistress, Lady Renko, because of the disruption she is causing in the clan. When an accountant tried to cut back her kimono budget, she told him slit his stomach. Even though they are in a time of economic distress she tries to have an old temple rebuilt so her father can become the abbot. When Sir Oibiya goes to Lord Tabu Ukyou and complains about the things that were going on, including the temple building plans, Lady Renko enters the meeting and tells him is insolent.
Expecting to be killed for what he has done, Sanzaemon is instead sentence to house arrest for a year. While imprisoned his deceased wife's niece, Rio, brings him food. We can see Rio starting to fall in love with Sanzaemon. We see Sanzaemon catch a bird with a pole, a skill, with a certain twisting move, that he learned as a child.
After the year is up, Sanzaemon is freed. After two he goes back to work for the Lord Ukyodayu, who it seems has forgiven him.
We see in a flashback that the people were restless and the Lord's brother Obiya has problems with the way his brother, Lord Ukyodayu, was ruling, much of which is to the detriment of the people, some of whom were starving. Next we see people getting their heads chopped off. These are the events that led to Sanzaemon action.
Sanzeemon gets his former pay grade back and is appointed as chief bodyguard. Something is wrong though because the Lord doesn't seem to like him. The clan elder, Minbu, asks Sanzeemon about a secret move he has called "Torizashi" (bird-spearing). Sanzaemon explains that it is a move he invented, and a man uses "Torizashi" only when he is in a desperate situation. we then find ou that Minbu is planning to use Sanzeemon's sword skills against Obiya's who he fears will try to kill his brother, the Lord.
Sanzeemon wants to find someone for Rio, but she wants to stay with him - forever. Sanzeemon who has been alone since his wife died decides he loves Rio too. But then a guilty Sanzeemon sends her away, but Sanzeemon says he will come for her, although he doesn't know when.
When Obiya comes in to the castle with his swords, the Lord is warned by Sanzeemon to leave. Sanzeemon then meets Obiya and tells him he can not pass. Swords are drawn and the duel begins. Sanzeemon does not want to kill Obiya, but with his back against the wall he uses the "bird-spearing strike" move and kills him. Monbu then comes in with dozens samurai and says that Sanzeemon has lost his mind, and they are to kill him. He is looking to get rid of a problem (Obiya), and then place the blame on a crazed person.
Sanzeemon is surrounded and begins killing his attackers, as so often happens at the end of samurai movies. Barely able to stand, he fights off twenty attackers. The last fight scene also could have been better. Sanzeemon is mortally wounded and can barely crawl, but a dozen samurai follow him but are afraid to attack him. In front of the Lord and Monbu, Sanzeemon is finally cut down but with one last thrust he kills Monbu.
Not bad, but could have been better. Pace is too slow, and flashbacks were more confusing than they needed to be. It would have been better if presented in a linear style with a faster pace. I also have some problems with the plot. If Sanzeemon is such a heroic character, sacrificing his life to kill the evil Lady Renko, why would he defend Lord Ukyodayu from Obiya?