Akira Kurosawa's original idea for the film was to make it about a day in the life of a samurai, beginning with him rising from bed, eat breakfast, go to his master's castle and ending with him making some mistake that required him to go home and kill himself to save face. Despite a good deal of research, he did not feel he had enough solid factual information to make the movie. He then pitched the idea of a film that would cover a series of five samurai battles, based on the lives of famous Japanese swordsmen. Hashimoto went off to write that script, but Kurosawa ultimately scrapped that idea as well, worrying that a film that was just "a series of climaxes" wouldn't work. Then, producer Sôjirô Motoki found, through historical research, that samurai in the "Warring States" period of Japanese history would often volunteer to stand guard at peasant villages overnight in exchange for food and lodging. Kurosawa then came across an anecdote about a village hiring samurai to protect them and decided to use that idea. Kurosawa wrote a complete dossier for each character with a speaking role. In it were details about what they wore, their favourite foods, their past history, their speaking habits, their reaction to battle and every other detail he could think of about them. No other Japanese director had ever done this before.
This was the first film on which Akira Kurosawa used multiple cameras, so he wouldn't interrupt the flow of the scenes and could edit the film as he pleased in post-production. He used the multiple-camera set-up on every subsequent film.
Akira Kurosawa designed a registry of all 101 residents of the village, creating a family tree to help his extras build their characters and relationships to each other.
As the production process grew longer and longer, producers grew worried that Akira Kurosawa was spending too much on the film. As a result, production was closed down "at least twice." Instead of arguing, Kurosawa simply left to go fishing, believing that the studio had already invested so much money into the film that they wouldn't simply scrap it. He was right.
Akira Kurosawa refused to shoot the peasant village at Toho Studios and had a complete set constructed at Tagata on the Izu Peninsula, Shizuoka. Although the studio protested the increased production costs, Kurosawa was adamant that "the quality of the set influences the quality of the actors' performances . . . For this reason, I have the sets made exactly like the real thing. It restricts the shooting but encourages that feeling of authenticity".
Tatsuya Nakadai: One of the samurai who is seen walking through the town. This uncredited bit part is the second known film appearance by Akira Kurosawa's regular, Nakadai, who would quickly become one of Japan's most accomplished actors. His active career continues more than 50 years after this film.
Akira Kurosawa: [names] Kikuchiyo is a girl's name made up of two parts, like Betty Sue in America. That's why the samurai laugh so hard at the name. Obviously Toshirô Mifune's character is illiterate, and it's a very subtle thing that the other samurai choose to tease him about the age and not choosing a girl's name! Kiku translates to "chrysanthemum" and Chiyo to "1000 generations". This is in fact one of several occasions in which Mifune's character in a Kurosawa film has a name composed of a plant and a number of years.
Akira Kurosawa: [weather] Lots of scenes from this movie feature rain to accompany the uneasy atmosphere of the situation, most famously the final battle scene.