Consider the kusarigama. Please. In medieval Japan it was a chain with a lead weight attached to a sickle. Swing the chain, snare a samurai, run up and finish him off with the sickle. A real working man's weapon.

In ninja fiction, however, a kusarigama is a chain with a knife on it, and the ninja swings the knife to deadly effect. Never mind physics, 'cause reality sucks. In “;Ninja Assassin”; the hero—well, the least objectionable coldblooded killer—whips around a kusarigama blade with all the brio CGI after-effects can muster. He's cutting people in half, right and left and up and down! It's a Niagara Falls of blood-splatter F/X!

“;Ninja Assassin”; is a completely deranged take on traditional ninja movies, with everything amped up to 11. You'd expect this from the Wachowski brothers, who are yanking the strings of director James McTeigue, who previously helmed “;V for Vendetta”; for the WBs. Like their earlier “;Speed Racer,”; this was also created in Germany and also stars Korean pop star Rain.

You can't swing a samurai sword without making a mess, and spurting arterials are the butter to ninja-movie bread. Although “;Ninja Assassin”; goes over the top in severing relations—literally—it's pretty much a letdown in every other department. We shan't count the ways, but here are a few:

» Everything appears to be shot in near utter darkness. This is to avoid the film getting an NC-17 gut-smut rating. It also makes the action nearly impossible to follow. Every once in a while a shiny blade or severed limb sails across the screen.

» And that's likely on purpose, as the choreography uses the tyro trick of getting in close on the stars, who obviously aren't doing their own stunts, and cutting away to razzle-dazzle whacks and whumps, staged in double time.

» The plot concerns a “;good”; vicious killer who's annoyed at his vicious-killer schoolmates in Ninja School, plus the vicious-killer headmaster, and so the movie is pretty much all about them trying to viciously kill each other. In the dark, most of the time.

» Rain. The movie stars Rain. There are real actors doing their best here—Sho Kosugi, Naomie Harris, et al.—but at the center of it all is pop twit Rain, replete with fake scars and scowl, and when the action starts it's obviously someone else, and he's never given more than a few words to say in a row, and when he has a flashback, even one only a few years old, the character is played by a completely different actor. Rain! Change your stage name to Drip.