(released as Tenchu! in the United States) is a 1969 Japanese samurai film directed by Hideo Gosha set during the end of the Tokugawa shogunate and based on the lives of the historical Four Hitokiri of the Bakumatsu. It is notable for starring the famous author Yukio Mishima.
Okada Izà  is a rà Ânin born into poverty who joins the , a group of Imperial loyalists based in Tosa and headed by Takechi Hanpeita. Izà  soon becomes a well known and successful killer, and he is stubbornly loyal to Hanpeita. However, Sakamoto Ryà Âma warns him that he is merely "Takechi's dog" and that Hanpeita will end up betraying him. After Izà  fouls a night attack by the Kinnà Â-Tà  on Ishibe Station by revealing his identity, Hanpeita's wrath at his blunder and resentment at his own subordinacy begins to test Izà Â's loyalty. Eventually abandoning Hanpeita, the regretful Izà  returns and apologizes. He is then ordered to assassinate the aristocrat outside the Sarugatsuji using the sword of Tanaka Shinbei. During his interrogation over Anegakà Âji's death, Tanaka commits harakiri after his recovered sword is presented to him as evidence. As Hanpeita becomes increasingly determined to succeed in his plan to become daimyo of Tosa by eliminating his opponents, it becomes necessary to sacrifice Izà Â, which he does by betraying him after he is arrested as a rà Ânin by the Aizu Mimawarigumi and later by trying to poison him with amygdalin-drugged sake (座æ¯ãÂÂãÂÂ). Izà  survives, but, disillusioned, confesses to his murders for the Kinnà Â-Tà Â, and is condemned to crucifixion. Before being killed, he is told that Hanpeita will be forced to commit harakiri.