Did I miss something?
Why was the mother blind and so old at the end?
We're told that ten years have passed, and then we see the scene where she doesn't look that much older and tries to run away. Her tendon is then cut.
In quick succession Zushio escapes, becomes governor, frees the slaves, resigns, and goes to Sado.
When he finds his mother at Sado, she has aged many years and even somehow gone blind.
Did something get mixed up in the editing? Was the scene in which the mother's tendon got cut supposed to take place shortly after her enslavement? Was it some sort of poorly realized flashback? The only reasoning I can imagine is that someone decided to put that scene after the passing of ten years so that the new slave singing the song would be more effective.
I have an open mind to thoughts here, and if I did miss something I apologize in advance.
Otherwise I thought it was a fantastic film.