Sanjuro

Nine young samurai, including his nephew, believe that the lord chamberlain, Mutsuta, is corrupt after he tore up their petition against organised crime and argued that maybe he himself was behind the crimes. One of them tells the superintendent of this and he agrees to intervene. As the nine meet secretly at a shrine and discuss their problem, a ronin (Toshiro Mifune) emerges from another room where he has been resting. The ronin has overheard their plans, and suggests that the superintendent is in fact the real corrupt official. While at first the samurai are insulted by his claims, they soon find themselves surrounded by the superintendent's men, proving that he was correct. Initially, the samurai want to fight, but the odds are overwhelming, so the ronin hides the samurai, confronts and hits a few of the attackers and bluffs their leader into leaving. The grateful samurai ask what they can do for the ronin so he takes only a small amount of money; however, after realizing that Mutsuta and his family must now be in danger, he decides to help the samurai bring down the corrupt officials. Read more on Wikipedia.