[Update 02/21/2021: need to redo this entire review and fix the screenshots.]
A samurai lives with his elderly mother. They once had a servant girl that he secretly (even to himself?) loved, but she (at the beginning of the film) was married into a merchant family. Fast forward three years and his mother is dead and by chance the samurai bumps in the ex-servant girl in the market. She tries to put on a happy face, but you can see she's hurting inside. Months go by and he continues his day-to-day activities as a lower samurai, which includes learning modern Western weaponry, then while hanging out with his sister he overhears her talking about how the ex-servant girl has be mistreated by her family and sick for two months. Infuriated by this news he goes to her home and finds her suffering from malnutrition and neglected. He takes her home and nurses her back to health. This doesn't sit well with the higher ups, so when an childhood friend of the samurai is found to be secretly plotting against the shogunate our hero is ordered to go kill him.
Anyway, this movie's great, almost as good as THE TWILIGHT SAMURAI, but not quite. I think Hiroyuki Sanada's performance in that film was so perfect that it was impossible for Masatoshi Nagase to match it. Also, the samurai in TTS had two adorable daughter's that would have been orphaned if he died, so that really ratcheted up the tension. All said and done THE HIDDEN BLADE is a excellent film.