Whatever you do, do not watch this anime.
If the premise of futuristic weapons in ancient Japan didn't scare you away, I hope this writeup does. The animation is awful. Not disappointing awful, but two frames flipped back and forth for a minute to show a man running awful. And the butchery of the English language in the translation (Revenge is used as a verb. More than once.) is enough to make a man vomit.
Unfortunately, there are even worse things. Like the unexplained aliens (!?!) at the end. The man who sits on a computer (!?!) in a secret room, commenting on how something must be done and doing nothing. The fact that the ninja clan had a stash of TNT around for emergencies.
You may think it looks like a decent ninja movie, and you may fail to heed my advice. For god's sakes, please don't fucking do this. You will be sorry.