For starters, there's "Red Warrior", which has samurai yelling war cries as part of the song.
Reportedly, he had been studying Japanese music to make sure he had it right, and was subsequently asked by Japanese composers how he had captured it so well.
Designated Hero: The audience is supposed to sympathize with the rebellious remnant of what, art and culture aside, amounts to a hereditary caste of armed thugs who retained carte blanche to abuse and kill commoners for offenses that we would find ridiculous and petty, who demanded exemption from taxation and to be the only ones allowed to fight and bear arms, and who had already led to countless military insurrections and would never stop. Samurai were rendered mostly superfluous during the relative peace of the Tokugawa shogunate, and they either spent their time absorbing resources produced by the peasants and prosecuting internecine conflict or were pressed into the role of bureaucrats (the forerunners of the modern Salaryman) or soldiers. Indeed, for the most part, modern Japanese history tends to cast the people who instigated the Meiji Rebellion (and subsequently staffed the modern Imperial government) as heroes, not as villains that destroyed Japan's warrior traditions, and only consider some of them as Well-Intentioned Extremist at worst.
The movie is surprisingly appreciated in Spain, as it draws big ratings every time it is broadcasted in TV and many Spaniards can recite its main quotes and dialogues verbatim. This became funnier when the Alatriste film adaptation became equally successful in Asia - apparently, there's something common to both samurai culture and 17th century Spain that makes them attractive to each other's countries.
The film was more successful in Japan than it was in America.
Harsher in Hindsight: Katsumoto's death, plus Algren's determination, show the Emperor and the Japanese people the value of Bushido. We all know how thatturned out.
One moment that can be funny with the right audience — ninjas bursting through walls. "Damn those paper walls. They can't keep anything out."
The Total War: Shogun 2 expansion pack Fall of the Samurai is focused around the modernization of Japan (as well as the conflict of conventional Japanese weapons against guns and cannons), with you being very capable of reenacting the movie's final battle.
I Am Not Shazam: Algren is not the last samurai, Katsumoto is. Or, alternatively and arguably more appropriately, the last samurai are Katsumoto and all of his men — the word can be read as either singular or plural.
Memetic Loser: Let us not forget the sad tale of the samurai Hirotaro, who was not only killed (while in full armor) by Tom Cruise while the latter was lying on the ground, unarmored, with a broken flag pole, but the latter then went on to be granted Hirotaro's armor and sword, be welcomed in with open arms by his friends, and kiss his wife. Talk about posthumously adding insult to injury.
"Tell me how he died." "I will tell you how he lived."
Mexicans Love Speedy Gonzales: At the time of release, Japanese audiences loved this movie, either in spite of or because of its Hollywood History - probably because, despite all the artistic licenses, the movie actually makes a pretty good Pragmatic Adaptation of the Satsuma Rebellion era and gives the Meiji Restoration a strong romantic flavor one rarely sees in modern international cinema. It's among the highest-grossing films in the country.
Moral Event Horizon: A certain massacre of a Native American village by Bagley, the raid being in response to attacks on his forces from around the region. Note that while it's clear that this event (which, while horrific, is implied to be nothing particularly notable from Bagley's point of view) causes Bagley to cross the horizon for Algren and presumably the audience, it's some way into the film before we actually learn why the latter hates the former so much.
For a movie that had pretty good fight choreography that was reasonably faithful to the martial arts involved, the way that Nathan killed Bagley is just bizarre. Nathan grabs a katana, reverses it in his hands, then throws it like a spear at his target. The throw itself - and the way the katana flies perfectly straight through the air - just looks weird, and that's not even getting into the fact that katanas are slashing weapons and are generally bad at stabbing, even when they're still in someone's hands at the time.
While intended to be a profound and heartbreaking death by honourable suicide, Katsumoto's contorted constipation face as Algren pushes the wakizashi into his stomach got a few members of the audience cracking up.
A poor samurai extra got kicked in the balls by Nathan's horse. It's hard not to gloss over it once the viewer notices what happened.
Narm Charm: In order to make Emperor Meiji sound adequately like himself, the European Spanish dub put a Japanese native, Naoto Muramatsu, to voice him, trying to give out the voice one would expect of a man of his status and physical build. His resultant lines, read with a monumental Japanese accent and a strangely androgynous, royal foppish tone, became virtually impossible to take seriously by Spanish audiences, but this only made them just as entertaining and memorable.
Protagonist Title Fallacy: The Last Samurai refers to all those samurai who fought in the climatic battle, not Nathan Algren. To be fair, the marketing seems to have done this deliberately (most of the posters were just Cruise in armor and the title). Part of the confusion is that Samurai can refer both to a single warrior and to a group, in this case it was the latter (and if read singly it would mean Katsumoto anyway). A fact completely lost on the translators of many countries:
In Sweden, they named the movie Den siste samurajen (the explicitly singular form); the plural form would be De sista samurajerna.
In Russia, Posledniy samuray, instead of Poslednie samurai.
In Italy, L'ultimo samurai, instead of Gli ultimi samurai.
In Spain and all the Spanish-speaking American countries, El último samurái instead of Los últimos samuráis.
In Finland, Viimeinen Samurai instead of Viimeiset Samurait.
In Czech Republic, Poslední samuraj, instead of Poslední samurajové.
In France, Le Dernier Samouraï, instead of Les Derniers Samouraïs.
In Poland Ostatni Samuraj instead of Ostatni Samurajowie.
Somewhat applies to the German version as well, where the title of the movie is Last Samurai (yes, it's in English), the lack of an article indicating that we're dealing with an individual and not a group.
Spiritual Successor: To Dances with Wolves. Both are about an American Civil War veteran who develops great respect and admiration for an alien lifestyle and culture, falls in love with a woman belonging to that culture, and fights against a larger and more modernized military force with which he once worked to defend that culture from being destroyed. While also wearing vestments from that culture.
Omura and Katsumoto are Japanese natives who are quite fluent in English. The Emperor also does a decent job of it at the end, although he speaks somewhat haltingly, and pauses at times to think of the right words. Nobutada barely speaks English but knows enough to get his point across in a few instances.
Algren knows Blackfoot, and in the span of one winter, learns to speak Japanese.
Multiple times