BTW you probably know this but although Sunrise is an expressionist film from a recently immigrated director it is an American movie.
The other of the classic Big Three Japanese directors (at least according to American consensus) is Mizoguchi. Ugetsu and Shansho the Bailiff are usually listed as his two best and probably are. Sisters of the Gion is my favorite of his pre-war movies.
If you like Yojimbo a non-Kurosawa movie you should see is Sword of the Beast, Hideo Gosha was a great director who doesn't get enough love in the states.
Another must see samurai movie, although it's not a western-esque action movie like Yojimbo and Sword of the Beast, is Harakiri by Masaki Kobayashi. If you like that one also see his Samurai Rebellion.