Because it's got it all. Sword swingin' ninjas, blinding violence, a fairly good plot, great character development, and, of course, the women. You may have seen some Japanese clips of this movie on MTV's Cartoon Sushi a few years back. The movie tells the story of master swordsman Jubei and his companions as they set out to stop the evil plans of the warlord Gemma.
Gemma plans to build an army of ninjas.
With this army, he plans to conquer the world. What makes things worse is that Gemma has gained the power of immortality, which comes as a surprise to Jubei, who thought that he had killed him years before. The journey starts when Jubei unwittingly kills one of the 8 devils of Kimon. These are Lord Gemma's personal guard. Throw in Jubei's love interest, Kagero, a ninja girl with a mysterious problem.