I only recently found out about this movie, I bought it on amazon and was amazed!
Macbeth is my favorite play of all time, Akira Kurosawa is my favorite director of all time, and Toshirô Mifune is my favorite actor of all time!
Compared to the Orson Welles 1948 MACBETH feature, which was a good movie in itself, Kurosawa, by taking this story into a Japanese setting, just made it more interesting to watch. Looking at it now, I'd wish that my high school English literature teacher would have shown this to us as well (but we only saw the Welles version). And of course, no one should underestimate the powerful onscreen presence of Toshiro Mifune!