Most of Christopher Lambert's filmography reads like a guide to B-movie hell. I got conned into watching this by a friend years ago, and will be forever grateful. The story is solid, Lambert turns in an almost-acceptable performance, and most of the rest of the cast does well. My favorite thing about the movie is the (by martial arts flick standards) realism. The gaijin does not miraculously learn to swing a sword like a samurai in a matter of weeks, months, or ever. The action sequences are exciting and fairly well-executed (by 1990's b-movie standards, at least), particularly a ninjas vs samuri scene on a Japanese bullet train. Some of the characters have a bit of complexity, there are a few little plot twists, and the character interaction is often believable. They also answer that age-old question "who'd win a fight between a middle-aged ex-athlete with a few months of kendo training and a ninja who's just lost an arm and leg"? (Lamberts's character is a former fencer turned businessman, but that bit's cut out of the home video/DVD version, as is the monologue by Kinjo the ninja, which helps to serve---in part, at least, as an explanation as to why this movie, set in Japan, has almost an entirely Chinese cast). If you're in the mood for an fun, entertaining, semi-intelligent B-action flick, I whole-heartedly recommend this one.
Oddly enough, the writer of "Pretty Woman" wrote and directed this flick, which may explain why my wife liked it, too. Of course, the same guy did a flick called "Cannibal Women in the Avocado Jungle of Death".