Ninja Assassin takes so many liberties with its title figures, there's not much of their real life counterparts left in them. The shinobi manifesto involves the utmost stealth; these fighters kill without their victims even knowing they were present. Compare that to Ninja Assassin, wherein characters make as huge a scene as possible. Of course, this is for the sake of entertainment and not reenacting history (the Shinobi No Mono series already did this). But even allowing for the leeway it requests, the film still asks a lot of viewers. This movie abides by no real rules and has its way with your senses until you pass out from overkill or disinterest.

For a while, ninjas have served as a pop culture running joke, but they're very much a reality here. Raizo (Speed Racer's Rain) is such a soul, raised amongst a clan of fighters bred for carrying out assassinations under cover of darkness. When an incident leads to a nasty split from his mentor Ozunu (Sho Kosugi), his fellow clansmen mark him for death shortly thereafter. Crusading cop Mika (Naomie Harris) is also on the trail of their covert killings and quickly becomes a target for Ozunu's ninjas herself. Luckily, she soon crosses paths with Raizo and joins forces with him to deliver a blow to Ozunu in the name of justice -- and vengeance.

Preconceptions people have about ninjas are fair game in Ninja Assassin. Ninjas usually get pitted against pirates in debates over which is cooler, so consider this film a glorified pro-ninja campaign ad. Everything these characters do here is for the purpose of looking cool, and if that means setting Newton's laws aflame, so be it. It wouldn't be a biggie if the film came packaged as a historical fantasy, but Ninja Assassin fancies itself a gritty crime drama. It ceases to be about ninjas being really, really good at what they do and more about what effects will fly at your face next. To be fair, it's sort of presented as a living comic book, but that doesn't prevent the illusion from shattering whenever Raizo picks up his mighty blade. Instead of enhancing the story, the slick style detracts from it -- quite a feat indeed, considering there's no plot to begin with.

Remember how Clive Owen's character in Shoot 'Em Up pretty much knew he was in a cheesy action flick and spent every over-the-top, carrot-impaling minute of it just living the dream? Imagine that without a trace of humor, and you've got yourself Ninja Assassin. The story really boils down to Raizo and Mika wanting to nail some ninja patootie, though it's taken so seriously as times, you'd swear the filmmakers mistook themselves for being involved in a Michael Mann production. Sure, the violence seems outlandish to the max, but seeing baddies spontaneously halved only leaves an impact for so long. The dour mood can also be traced to Rain, who I'm sure is a talented dude but exhibits next to no charisma. I can't even commend his work in the action sequences, since you never know if you're watching him or some computer effect. Harris does well, though she's too gifted to spend her career nearly getting shurikens up the nose.

Watching Ninja Assassin is like seeing someone play a video game you're not really sure you want to play in the first place. Not just any game, mind you, but one you can find for $10 at Wal-Mart and enjoy solely as a novelty shared between friends. While Ninja Assassin's geysers of gore may offer some entertainment, never have so many exploding heads elicited so many yawns from yours truly.

MY RATING: ** (out of ****)

(Released by Warner Bros. Pictures and rated "R" for strong bloody stylized violence throughout, and language.)