The movie stars Sonny Chiba as Jube Yagyu (son of a fencing instrutor) and also features Toshiro Mifune in a smaller role as Lord of Owari. Set in 1824 with the death of the second Tokugawa Shogun. When it was discovered that he died from food poisoning, there was a problem with who should be the heir. His eldest son, Iemitsu, stuttered and was disfigured. His second son, Tadanaga was bright and popular was backed by the counselors but Iemitsu had supporters too, including Yagyu. Iemitsu's supporters poisoned the Shogun when they found out he wasn't going to choose Iemitsu as his heir.
Iemitsu is at first very angry at what his followers had done, but when he finds out he was to be passed over, he understands what they have done. The two brothers, both pushed by their followers, begin a struggle against each other. Iemitsu's main supporter is fencing instructor Yagyu, who is pulling many of the strings behind the scene to advance his own aims. Prince Tadanaga is pushed on by his mother and by his advisor Doi.
Different factions join different sides, while the emperor and his supporters look on happily as the Shogun's power weakens in the struggle and refuse to name a successor to the Shogunate. Many ronin join in with Tadanaga as he begins to make his preparations. Everyone in Japan seems to be picking a side. Fights seen to break out all over the place as the two sides fight for control. Ogasawara Gensinsai, a swordsman who has a rival school to Yagyu pops in to challenge him. There is a lot going on, probably too much to follow in one viewing.
Fights break out and a woman samurai, Akane, who is Yagyu's daughter is killed. Sonny Chiba shows up in an eye patch as Yagyu's son Jubei. It's a little hard to keep track of who is fighting for what side, and it is even harder to figure out why they are fighting for a particular side.
The emperor's advisers see all the confusion as a chance for them to exert their power. They can get back all the power they have lost to the Shogunate if they play their hand right. Both the brothers are trying to get the Emperor to back him, but the Emperor is in no hurry. Tadanaga is having ronin attack his brother, who is travelling to see the emperor, since he can't do it openly, and he supplies them with guns. But Iemitsu sets a trap for them and cuts them down.
Yagyu then brings a message from the Shogun, Iemitsu, ordering Tadanaga to commit seppuku, which he does. Government troops then massacre the village of ronin, with their women and children. Yagyu then duels Gensinsai and Yagyu wins. Iemitsu is then appointed as the third Shogun by the emperor.
Jubei, who had been betrayed by his father, then shows up and kills Tadanaga and brings his head to his father, whose arm he then chops off.
The film has a TV look and feel. The music is really dramatic and intrudes on the film. The dialogue and acting also seem a little forced. There are also just too many people coming in and out, and the story was difficult to follow. But overall, the movie had good production values with an epic feel to it, and was fun to watch.