Japanese actor Hiroyuki Sanada stars as the main supporting character, Kuranosuke Oishi, a leader of the men. Sanada said that during the filming Reeves became more and more of a samurai, while the character he played became more "wild" in style.
Sanada said Reeves and himself hoped to depict the friendship of two characters, which transcended borders and social positions, in the film.
Reeves said "47 Ronin" is a story where people "share this journey to reclaim their land, their honor, their way. It was very special to me to be part of it."
Reeves, who grew up attracted to martial arts movies, makes his directorial debut this year with the martial arts action movie "Man of Tai Chi."
The film "47 Ronin" premiers in Japan on Dec. 6 and opens in U.S. theaters on Dec. 25.