Basic Plot of Yojimbo

1. A Samurai (who later calls himself Kuwabatake Sanjuro...30 year old mulberry field) randomly chooses a path leading to a town.
   
2. The first thing he sees is a young man leaving his family and farming to join in the gangs in the town.
   
3. After speaking with Hansuke, the town's corrupt constable who demands a bribe, the samurai takes refuge at inn of Gonji who further explains the situation in the town. There are two factions, one led by Ushitora they other led by Seibe and they are waring. The Ushitora are allied with Tokuemon, the sake brewer, and the Seibe with Taezamon, the silk merchant. Taezamon is also the increasingly insane town mayor but the Ushitora insist that Tokuemon is now mayor. Gonji tells the samurai to leave but the samurai suggests both that he likes the situation in the town and that he can help.
4. The samurai agrees to be Seibe's bodyguard/swordsman but overhears Seibe’s wife scheming to murder him rather than paying him after he wins.
5. Believing that with the samurai's help, he will defeat Ushitora, Sebei calls for a fight but, when gangs line up to fight, the samurai abandons Seibei and watches the fight between Ushitora and Sebe's men.
6. The fight is interrupted by arrival of an official from the central government..
7. Under pressure, both sides agree to truce but Ushitora has sent two assassins to kill officials in another town so that the Edo official will leave.
8. The samurai captures the two assassins after they have successfully killed the official. He brings them to Seibe but tells Ushitora that Seibei has captured his assassins.
9. As a result, and to get his men back, Ushitora kidnaps Yoichiro, Seibe’s son.
10. The sides agree to a swap: Ushitora’s assassins (held by Sebe) for Seibe’s son (help by Ushitora).
11. However, the exchange is foiled when Unosuke, Ushitora’s deranged brother, kills the assassins. Unosuke possesses and fetishizes a gun (follow this optional link for a nice essay on Kurosawa and guns).
12. Seibe however, has anticipated the double cross so has kidnapped one of Ushitora’s women who is exchanged for Seibe’s son the next morning.
13. This woman is Nui, a local farmer’s wife who has been given by Ushitora to Tokuemon, the sake brewer, to gain his alliance. Ushitora holds her as a captive.
14. The samurai kills Ushitora's thugs who are guarding the woman and frees her. He tells her to flee with her young son and husband. He gives them money. When he is questioned by Ushitora, he blames their escape on Seibei’s men.
15. All out war breaks out as a result, with Ushitora attacking Taezamon's silk warehouse and Seibe attacking Tokuemon’s sake warehouse.
16. However, Ushitora realizes the deceit, captures and tortures the samurai.
17. The samurai escapes, flees to Gonji at the inn. Gonji tells Ushitora that the samurai is with Seibi.
18. As a result, Ushitora attacks and completely destroys Seibei. The attack is witnessed by the samurai.
19. Taken to the cemetary, by Gonji, the Samurai heals but then Gonji is taken prisoner by the Ushitora.
20. The Samurai returns to rescue Gonji, killing Ushitora and Unosuke (after allowing Unosuke to attempt to use his gun to kill him).
21. Taezamon, insanely banging his drum, murders his rival Tokuemon.
22. Samurai spares life of the young man he met at the beginning, tells the corrup constable Hansuke to hang himself, and turns village over to Gonji. He then leaves.