In 1185, the Heike family fights against the Minamoto family. After a bloody naval battle in the Pacific Ocean, Yoshitsune Minamoto defeats the enemy and the survivors commit suicide. When the triumphant Yoshitsune arrives in Kyoto, his brother, the Shogun Yoritomo, is uneasy and orders his men to arrest Yoshitsune. However, Yoshitsune escapes with six loyal samurai led by Benkei and they head to the country of his only friend Hidehira Fujiwara. Near the border, after crossing the forest disguised as monks, their porter discovers that they are Yoshitsune and the six samurais and advises that the fearful Kajiwara and his soldiers are waiting for them in the border to arrest them. Yoshitsune disguises as a porter and at the barrier at the border, Benkei has to convince Kajiwara that they are six monks traveling to collect donation to build a large temple in Kyoto.
In 1945, Logan is held in a Japanese POW camp near Nagasaki. During the atomic bombing of Nagasaki, Logan rescues an officer named Ichirō Yashida and shields him from the blast.
A retired samurai must redeem himself for a crime that he committed earlier in his life. A squire is sent by the prime minister of Japan to keep watch over him.
Un samouraï du nom de Daiemon qui détenait le record du nombre de flèches tirées sur une cible en une journée avec 6200 flèches, lors du tournoi annuel qui se déroule au temple Sanjūsangen-dō de Kyoto, est détrôné l'année suivante par Kanzaemon Hoshino qui parvient à toucher 8000 fois la cible. Un panneau au nom de sa famille célébrant l'événement est apposé sur le temple en remplacement de celui de Daiemon, apportant un grand prestige à la famille Hoshino. Lors du concours suivant, Daiemon échoue à retrouver son bien avec « seulement » 7300 flèches ayant touché la cible et se suicide par seppuku.
Le seigneur de guerre Oda Nobunaga vainc rapidement ses ennemis dans sa quête de pacifier et d'unifier le pays sous son autorité. Il existe cependant une région que lui-même craint : la province d'Iga où vivent les ninja de l'école Iga-ryū, connus pour posséder des armes de guerre extraordinaires, ne pas penser comme des humains et assassiner pour de l'argent. L'un de ses ninjas, Mumon, reconnu comme un assassin exceptionnel et qui n'a pas d'égal au combat, a gagné le surnom de « ninja le plus fort d'Iga ». Il est cependant également paresseux et cherche seulement à gagner de l'argent pour plaire à sa femme, Okuni. Dans le même temps, un ninja nommé Heibee Shimoyama devient désabusé par la manière de vivre de son peuple.
Une force spéciale de la police impériale constituée de samouraïs est mise sur pied pour lutter contre le crime. Son ennemi n° 1 : Nizaemon Kumokiri, un bandit de grand chemin dont personne ne connaît la véritable identité, qui multiplie les cambriolages audacieux dans les demeures des riches commerçants.
Mataemon Araki (Toshiro Mifune), a renowned swordsman, helps a young man find vengeance. The opening scene has Araki sternly accosting Jinza with a formal proclamation of vengeance for the killing of his family member. Jinza (Takashi Shimura) cackles villainously and an epic fight commences.
Following the massacre of many thousands of Christians by soldiers of the Tokugawa Empire after the Shimabara Rebellion, Shiro Amakusa renounces the God who he feels abandoned them, and bargains his soul to the forces of darkness for the power to take his revenge. He gains the power to resurrect the dead, and begins with Hosokawa, the wife of a samurai who mocked her for her chastity and then left her to die during the invasion. Shiro restores her beauty in exchange for her loyalty. Next, they travel to the cave of legendary swordsman Miyamoto Musashi, who regrets that he neglected his lovely wife to find more opponents to duel, and that his advanced age prevents him from challenging the one rival he considered worthy to test his technique. He initially resists the pair, but suffers a heart attack and agrees to join them. During this exchange, his cave is visited by Yagyu Jubei, son of a samurai master and a powerful swordsman in his own right. Jubei rushes to Musashi's aid only to find an empty suit of armor. The unholy trio then encounter Inshun, a Buddhist monk who is plagued with terrible fantasies of sex and death. Hosokawa taunts him with the failings of his monastic teachings, and he commits suicide in despair, becoming one of Shiro's undead in the process.