There is some confusion with this movie. 'Sanjuro' at the international box office was the unambiguous sequel to 'Bodyguard'. The hero, played by Toshiro Mifune, is named Tsubaki Sanjuro instead of Sanjuro Kuwabatake. The change is as significant as it is unimportant - the roots of this movie are in the genre of westerns, for which the type of hero is more important than his personality. The heroes of John Ford, Jimmy Stewart or Clint Eastwood in each movie get new names and slightly changed biographies, but this is hardly important. American roots are crucially important here: 'The Bodyguard' relied heavily on tabloid American literature, and Kurosawa himself never hid his borrowings from Hollywood - he repaid it generously.
Despite the apparent disregard for psychology, the hero Toshiro Mifune noticeably evolves. He is no longer an adventurer who takes up the task of saving innocent people, but a teacher who realizes that without him everything will fall apart. But he's a very peculiar sensei. He emphatically disregards subordination and does not want to fit into the local system of relations: a serious conversation - he eats, everyone is running around - he sleeps.
The camera is predominantly static. The geometry of the frame is extremely strict. The disciplined space subjugates everyone except the protagonist. His relaxed movements, sloppy hairstyle, and lively facial expressions contrast vividly with all the other characters and with the plasticity of the frame.
But this is by no means idle relaxation, but saving energy before the decisive battle. Laconic and few battle scenes here give a head start to its predecessor - choreography honed to a shine, extended duration of the frame. Almost complete absence of musical accompaniment is replaced by excellent work with sound. There is noticeably less blood and severed limbs, but he has no shortage of cruelty. Kurosawa does not revel in it. The incredibly impressive final fight is the bloodiest and most spectacular episode of the movie, but it is also the scariest. It is by no means a happy ending.
Kurosawa's important question about the justification of violence resounds here. He is a rare kind of pacifist who understands the necessity of violence but in no way justifies it. In 'Seven Samurai' no one even thanked the heroes for saving the inhabitants. Here, the protagonist himself doubts the justification of what he did, despite the generous thanks from the locals.
But Tsubaki Sanjuro is not obsessed with reflection, so he simply leaves, deciding to leave everything as it is. But he won't be coming back here again.