Araki Mataemon was a very strong warrior, and his feud against the samurai Kawai Matagorō is one of the most famous in Japan. Matagoro killed Gendayu, the little brother of Mataemon's brother in law, Watanabe Kazuma. Becoming a murderer out of jealousy for a childhood friend, Matagoro fled in another domain, using friends of his father and his lineage linked to Tokugawa Ieyasu. It was somehow a complicated matter, as it seems at that time, a law from Toyotomi Hideyoshi allowed a little brother taking revenge for his elder brother, but not the reverse. After some years, the lord of Kazuma and Mataemon found a way, and they were allowed to take revenge for the murder. They fought and killed Matagoro and just one other samurai who was helping the culprit. It seems at that time, Kazuma was Mataemon's only assistant.

Watanabe Kazuma's younger brother is brutally murdered by Kawai Matagoro. However, Kazuma's vendetta is denied since the Japanese law in the 17th Century only allowed a samurai to avenge his father or older brother, but not a younger brother. This incident makes his family member Araki Mataemon face his best friend in order to clear path for Kazuma. The tension mounts as they must carry out the vengeance before the murderer Kawai Matagoro reaches the safety of a direct retainer of the Shogun.

Watanabe Kazuma and Kawai Matagorō from the Bizen Okayama Ikeda clan were close friends, but they inevitably became enemies after Matagorō killed Kazuma's younger brother, Gentayū, and fled. Seeking assistance, Kazuma asked his brother-in-law, Araki Mataemon, for help, but Mataemon refused, saying that it was against the code for a brother to avenge another brother's death. On the other hand, the lord of the clan, Ikeda Tadao, ordered a search for Matagorō, who was found to be sheltered by the Hatamoto, including Andō Jiemon, in Edo. Tadao was furious but unable to act. Matagorō, in Edo, came to regret his birth as a samurai. He met and fell in love with Okō, a bathhouse maid. As the discord between the Hatamoto and the Ikeda clan deepened, Tadao died of illness. Seizing the opportunity to ease the conflict, the shogunate ordered the Ikeda clan to be succeeded by the young lord Katsugorō and to relocate to the Ikeda clan of Inshū Tottori. Meanwhile, Matagorō was exiled from Edo.

The famous showdown at Kagiya corner has been told many times, but never before with the realism and intensity of this version scripted by Kurosawa Akira and starring Mifune Toshiro as the famed swordsman who must face his best friend as they are forced to take opposite sides in a vendetta caused by the murder of a family member. Told mostly in flashback as the avengers await the arrival of their quarry, this film displays true heroism in the face of fear as most of the combatants, while of the samurai class are not skilled swordsmen. They contrast sharply with the true warriors involved in this battle. Araki Mataemon (Mifune), who was not only a direct student of Yagyu Munenori, but the founder of his own sword style under the Yagyu name is a powerful force ready to assist his brother-in-law against the murderer's allies that include not only another noted sword teacher, but the deadly spear of Katsumi no Hanbei.