The character Nathan Algren, portrayed by Tom Cruise, is a disillusioned, drinking-troubled Captain who’s given an opportunity after the American Civil War: a well-paid job in Japan training new soldiers to build up a permanent Imperial Army. Upon his arrival, he's introduced to the young Meiji Emperor, and it becomes apparent that his main role is to help Ômura, the Prime Minister, develop a military force strong enough to overcome the traditionalist Samurai clan led by "Kausumoto," played by Ken Watanabe. The initial battle doesn’t unfold as expected, resulting in Algren's capture. During a difficult winter, he develops a connection with his captor, and the film starts to show us the honorable qualities, principles, and sometimes harsh fairness of this man. It blends historical elements with fictional ones in an intelligent, unemotional way; Watanabe’s performance is thoughtful and captivating as someone standing on the edge of a new period that neither he nor his people desire or fully grasp. Cruise clearly championed bringing this visually appealing story to life, and deserves credit for doing so, but he isn't particularly convincing in the lead role—the character requires a level of refinement that he doesn’t quite bring to it. There’s also an odd appearance by Scottish comedian/actor Billy Connolly, who initially recruits Algren – with a noticeably inconsistent accent. Masato Harada is effective as the scheming Minister who wants his society to evolve and prosper, and Shichinosuke Nakamura portrays the Meiji Emperor with a touching vulnerability that contributes to the film’s sense of realism. The production values are consistently impressive, particularly during the often-violent battle sequences.

Source on TMDB