The fictional plot is set in Japan in 1587, which is the 15th year of Tenshō.
People in a village are worried about thieves and decide to get samurai to help defend them. It is hard to get enough samurai. The samurai that help do it for different reasons. There is a lot of planning while they are waiting for the thieves. There is a big fight with the thieves at the end.
The Magnificent Seven was an American movie Western with a similar story. This is called a remake.
The movie was also adapted into an Japanese anime series in 2004 by GONZO, entitled Samurai 7. The anime series takes a more futuristic and fantasy take at the original story, replacing robots for thieves and bestowing superhuman abilities to the 7 samurais.
The Seven Samurai Facts for Kids. Kiddle Encyclopedia.