Although this does not have the same intensity as Hara Kiri, this film is definitely worth seeing. Like all good Japanese sword fight movies it has a very deep message. The message is about honor and upholding principles even if it involves giving up one's life.
Toshiro Mifune plays a retainer, Sasahara, to a certain lord who divorces his very headstrong wife, Ichi. This wife, Ichi, eventually is given to Sasahara's son resulting in a happy marriage. However the lord asks, no demands, that Ichi be returned to him despite the fact that she is happily married. Sasahara and his son become enraged and refuse to comply with the order given by their lord. The consequences are dreadfully intense!
The sword fights at the end are awesome especially the duel between Sasahara and Tatewaki, Tatsuya Nakadai. Again, although not as moving as Hara Kiri, this is definitely worth seeing.