Saya-Zamurai (さや侍, Scabbard Samurai) is a 2010 Japanese film directed and written by Hitoshi Matsumoto.
He is Kanjuro Nomi, a samurai who wears an empty scabbard because he has lost his sword and with it his honour, while she is his daughter Tae.
Surviving several assassination attempts by bounty hunters, he is captured by a rival clan and sentenced to The Thirty Days.
This practice has arisen because the little crown prince has not laughed since his mother died in the epidemic that also carried off Nomi's wife.
She has the idea of allowing the public into the palace to cheer him on, and she also sneaks into the depressed little prince's bedroom to try to gain his sympathy.