Out of the martial arts films I’ve seen so far this is the most grown up. It's also the least comprehensible. Between all the random fighting there is a sleazy prostitution ring storyline, complete with naked flesh and a brutal torture scene.
There is also a rather nasty rape scene, but the girl gets her revenge.
A side story concerns two ninja clans fighting over a statue but there is no focus on this for the majority of the movie.
Usually I would say this kind of thing is nonsense but fun, unfortunately the rape scene spoiled it for me.