Sanada Yukimura was a real historical figure who helped defend Osaka Castle in 1614 and 1615.
The actor Nakamura Kankuro VI (Sarutobi Sasuke in the movie) is from a kabuki acting family. The family had been in the acting in traditional Japanese kabuki theatre sine the 1800's.
This movie was released in September 2016. The Japanese national TV channel NHK had been showing a weekly TV historic drama "Sanada Maru" since January 2016. 50 episodes were aired.