This is one of those "movies" that was created by splicing together two or more episodes from a TV show. MST 3K used a few of those and they all stink. If the movie is not fun to watch, jokes don't help and this movie is both stupid and boring.
Lee Van Cleef plays a martial artist (a Ninja) but he is too old for this role. Yes there martial arts masters this old, but they are teachers not fighters. Timothy Van Patten, Van Cleef's sidekick (and disciple), is a terrible actor and he gets romantically paired up with a series of petite young women who all look like they are no older than 16. We are supposed to like him because he drives a van. I know that sounds dumb, but people in the 1970s actually thought that vans were very cool.