In the film The Last Samurai, there is a scene where the samurai get attacked by ninjas. It's a cool scene, but as far as I could tell it was never explained.
Where did the ninjas come from? Were they hired by the emperor? For someone trying to become more Westernized, hiring ninjas didn't match his style. Plus, if the ninjas found the samurai, why wouldn't they send the army next? On the other hand, if they weren't hired by the emperor, then why were they attacking the samurai? What did they hope to gain? Shouldn't they be on the side of preserving Japanese culture, just like the samurai are?
Has there been any explanation (in the film or elsewhere) as to what the ninjas were doing in this movie, other than looking cool and randomly killing people?