Musashi Miyamoto (Toshiro Mifune) is seen carrying two swords. This was a samurai custom known as daisho. Translated this means 'big-little'. The bigger of the two blades was the curved katana, which was generally used for combat and duelling. The short sword was the wakizashi, this blade was generally associated with committing seppuku, however, as can be seen in the film was also used for combat.
This film is part of the Criterion Collection, spine #15.
This film belongs to two distinct Japanese genres. While it is a jidaigeki (period drama), so too is it a chanbara (sword fighting film).