Moritsugu Katsumoto is one of the main characters of the movie The Last Samurai. He is portrayed by Ken Watanabe.
Katsumoto is the current patriarch of a line of samurai that have faithfully served the Emperor of Japan for hundreds of years. He is a charismatic leader, an excellent field commander and tactician, a philosopher, and a student. He speaks fluent English by the start of the events in the film.
Katsumoto has one son, Nobutada (Shin Koyamada), who shows great promise as a warrior, particularly with the bow. He also has a sister, Taka (Koyuki), who manages her household in Nobutada's village. Taka is married to Hirotaro, a samurai, with whom she has two boys. Katsumoto shares a strong relationship with the current Emperor, for whom he served as a teacher when the Emperor was young.
At the beginning of the events in the film, Katsumoto leads a faction of samurai rebelling against the Emperor. Though he reveres his former student, he believes that the old ways of duty, honor, and sacrifice (Bushido) are being displaced by the increasing modernization and Westernization of Japan. His hope is that the rebellion will convince the Emperor to not let the old ways be abandoned, and that the Emperor will understand Katsumoto still serves him. Katsumoto's actual enemies are the Emperor's advisors, most notably Omura (Masato Harada), a businessman who grows rich with the expansion of his cross-country railroad. Omura's influence over the Emperor is such that he is effectively running Japan.
While meditating, Katsumoto has a vision in which a white tiger fiercely defends itself against armored samurai in a misty forest. At the time, he is not certain of the meaning of the vision.
Katsumoto's rebellion attacks the railroad expansion, forcing the Western-trained soldiers of the Emperor to battle. Though the soldiers have the advantage of modern firearms, they lack experience and proficiency with the new weapons. Additionally, Katsumoto's reputation is such that General Hasegawa (Togo Igawa), the highest-ranking soldier in the Emperor's army, refuses to directly fight his former compatriot. The two forces meet in a misty forest, and the samurai lead with a cavalry charge supported by flanking infantry. The Emperor's soldiers are routed while the samurai take minimal losses.
Captain Nathan Algren (Tom Cruise), a veteran of American wars and instructor of the Emperor's soldiers, is present at the battle. Though he initially defends himself well, defeating multiple samurai, he is eventually dismounted and wounded. It is at this point when Katsumoto first sees Algren, surrounded by several samurai, defending himself with a spear decorated with a pennant of a white tiger. Katsumoto believes this is the white tiger from his vision.
Algren inevitably tires from fatigue and blood loss. Hirotaro moves into position for a deathblow, but leaves himself open to a fatal counter from Algren. Katsumoto orders the remaining samurai to spare Algren's life. Before departing the field, Katsumoto assists Hasegawa in committing seppuku. The force moves to Nobutada's village in the mountains to rest and recover during the winter.
Though Algren is initially hostile, over time he comes to appreciate and respect the samurai way of life. This is in no small part to Katsumoto, who not only ensures his safety but has many long conversations about various subjects. Katsumoto helps teach Algren the Japanese language and allows him to learn Japanese fencing. Katsumoto learns more about America, partly through Algren's journal that records his experiences as a US soldier. In one conversation, Katsumoto shares a belief with Algren that a life spent looking for the perfect cherry blossom would not be a wasted life.
Once the spring thaw melts the snow in the mountain passes, Katsumoto is granted safe passage by the Emperor. He returns the journal to Algren, noting that they were enemies when it was first taken. Katsumoto escorts Algren to the capital, from which he parts ways.
Katsumoto shares a private meeting with the Emperor, exhorting him to lead his people and return to the old ways. During an advisor's meeting soon after, Omura attempts to arrest Katsumoto for violating the new law against bearing a sword. Katsumoto notes that only the Emperor may forbid him from this, genuflecting to the Emperor in an attempt to inspire. However, the Emperor acquiesces to pressure from Omura, and Katsumoto is arrested and confined to his estate in the capital.
While meditating in his quarters, Katsumoto is presented with a tanto by one of Omura's men (John Koyama) with the hope of convincing Katsumoto to kill himself. However, Katsumoto is rescued by Algren and several samurai. During the escape attempt, Nobutada is critically wounded by gunfire. Katsumoto shares one last moment with his son, who asks his father to let him stay and cover the escape. Though Katsumoto is brought to tears, he eventually steels himself and withdraws along with Algren and several samurai. Nobutada occupies the enemy soldiers long enough for the others to get away, but he is killed in the process.
Dispirited, Katsumoto feels that his rebellion is a failure, and that the time of the samurai is over. He is convinced by Algren that a final stand may at last inspire the Emperor, so he returns to Nobutada's village to gather his forces and prepare for battle.
Shortly before the battle, Katsumoto presents a sword he had forged for Algren. The sword is inscribed with kanji that note it belongs to the warrior in which the old ways are joined with the new. Katsumoto then rallies his samurai and gathers on the field. The Emperor's soldiers are numerous, better trained, and even better equipped than before, most notably with howitzers and Gatling guns.
Through clever strategy and misdirection, Katsumoto's forces divide and eliminate a large portion of the Emperor's army. Unfortunately, many samurai perish in the process, at which point Algren observes they will not be able to withstand another assault. Katsumoto gathers the remaining samurai for a final cavalry charge.
The Emperor's forces form up a line, and though they kill some of the rallying samurai, they are unsuccessful in breaking the charge. The samurai advance upon the command position of the Emperor's army, nearly reaching the top before being cut down by the Gatling guns. Only Katsumoto and Algren are left alive, though both are gravely wounded. Katsumoto tells Algren that the American has regained his honor, and implores Algren to help Katsumoto die with his honor. Katsumoto then commits seppuku, and while dying, observes a small field of cherry blossom trees. His last words are that all the blossoms are perfect.