Shinobi No Mono is a classic Ninja movie filmed in 1962. It tells the tale of a Ninja named Goeman who is manipulated into trying to assassinate Oda Nobunaga, an evil warlord, who’s goal is to rule feudal Japan. The leader of both villages is really the most interesting person in this one as he has placed himself in charge of the 2 villages and disguises himself in each, to play them off one another to reach his goals. So he sets conflicting tasks for each village’s Ninja in the hope that he can kill Nobunaga. Goeman just happens to play right into his hands in allowing him to manipulate him.
The movie is subtitled and only available in SD on streaming but worth it for the fact that it was one of the very first Ninja movies ever made. You also get to see many “Ninja tactics” in action which is always fun. You can find the full movie on Youtube but the subs are wildly inaccurate in that version. I tried watching it there first and then just ended up grabbing it on stream (Amazon Video).