This is a ninja movie from Joseph Lai and Godfrey Ho... For those that don't know the history, These guys made a bunch of ninja movies during the 80's that were created by combining ninja footage (with mostly European actors) into really bad Hong Kong films...
The ninja's usually wore headbands that said "ninja" on them, and in general the movies were incredibly funny. Unfortunately, this one just barely fits in with the rest of them. All the primary actors from the other films are missing (except for the opening credits) and it appears that this one is not really a cut and paste movie... If it's a combination of two movies it's much more difficult to tell than usual and certainly more effort was put into hiding it.. possibly even using some of the same actors from the original movie or finding decent look-alikes... I still get the feeling that there is something not quite right about it, but who can be sure? It could just be constructed very poorly.... It definitely feels that the ninja stuff is out of place somehow, but it's not as obvious as the other films.
Anyway, on the surface, It seems that they were trying to make a real movie this time, but they failed to make it entertaining. It's mostly a softcore sex film with some poorly choreographed martial arts mixed in. There is very little of the charm contained in the other movies and it's generally pretty boring.
The plot makes absolutely no sense, which isn't necessarily a bad thing (you don't expect these films to make sense anyway). There are some very funny lines and a few of the fights are kind of amusing so i wouldn't skip it altogether. Just make sure you aren't expecting the standard Joseph Lai/Godfrey Ho ninja film or you will be disappointed.