Shogun's Samurai, known in Japan as , is a 1978 Japanese historical martial arts period film directed by Kinji Fukasaku. The film is the first of two period films by Fukasaku starring Shinichi "Sonny" Chiba as Jūbei Mitsuyoshi Yagyū, the other being Samurai Reincarnation. The film was adapted into a 39-episode TV series, The Yagyu Conspiracy (1978–1979), and two TV film remakes were released in 2008 and 2020. Plot In 1624, shogun Tokugawa Hidetada of the Tokugawa shogunate dies at Edo Castle. Komuro Kihei, his taster, also kills himself, leading to suspicion that the shogun was poisoned. Hidetada's oldest son Iemitsu was to be heir, but his father disliked his appearance and stammer and preferred his second son Tadanaga, who is bright, handsome, and admired. Hidetada's wife Oeyo uses her influence on other ministers such as the lord of Owari, Chief Chamberlain Doi, and Councilor Sakai, who join her in backing Tadanaga as heir. The young Chamberlain Matsudaira and Lady Kasuga, leader of the harem, back Iemitsu. The scheming nobles Sanjo Saneeda and Karasuma Ayamaro hope for the downfall of the government altogether. Ninjas hired by Doi enter the shogun's tomb in Zojo Temple and cut out his heart, but it is stolen from them by Yagyu's daughter Akane. Yagyu, Iemitsu's fencing instructor, determines that Hidetada was poisoned and confronts Chamberlain Matsudaira and Lady Kasuga. Matudaira ends up admitting to Iemitsu that he poisoned Hidetada and Yagyu explains that Kihei put arsenic in his father's food for three days to poison him. The lovers Hayate and Mon become independent Negoro fighters attempting to reclaim their homeland in Yamato Province that was taken 20 years earlier. They receive a request, ostensibly from Tadanaga, to aid the young prince. Jubei returns just as they resolve to aid the prince and he helps them kill Koga ninja spies in the woods. Doi tells Tadanaga that his father was poisoned by Iemitsu's retainers and Tadanaga confronts Iemitsu about it but Matsudaira and Lady Kasuga deny it and Iemitsu refuses to allow the body to be examined. Tadanaga invites his mother to move with him to his large estate in Suruga. Akane and her brothers meet with their brother Jubei and the Negoro fighters at the Tama River on the outskirts of Edo. Yagyu asks Sagenta, leader of the Negoro, to let the new female fighter Mon work for him. Doi resigns his office, complaining