Tom Cruise spent almost two years in preparation for this movie, including swordplay instruction and Japanese-language lessons.
This not only marks the first time Ken Watanabe starred in an American-made movie, but it is the first time he spoke English in a movie.
The swordsmith in the village is a real swordsmith. His name is Shoji Yoshihara, brother to Yoshihara Yoshindo. Shoji is a "Mukansa"-level master swordsmith, one of the highest rankings in Japan.
Contrary to popular misconception, the title of this movie does not refer to Captain Nathan Algren or Katsumoto. The word "Samurai" here is in its plural form, and referrs to Katsumoto's clan as a whole.
Although this movie seems to imply that Japan's new army was trained by the Americans, in fact, it was the Prussian General Staff that assisted in the modernization of Japan's army.