The film starts out with diagrams of the human penis. Then it moves on to war pictures and film clips, explosions, bombs dropping, and random acts of violence. About 30 seconds into this, is a film clip of some teacup ride at some crappy amusement park, then EXPLOSION! Back to the war clips. After a while, it goes to a samurai (IZO) getting speared to death while being crucified. IZO then comes back to life (though years later in the movie) and starts killing everyone.
This is a totally fantastic movie! It's got a really deep plot (if you want that sort of thing), but it's easy to ignore, so if you just want random violence then sit back, ignore the dialog and focus on the 100+ murders that occur in this movie.
IZO has everything, including a part where IZO is sucked into a lake, and somehow appears at a wedding, so what does he do? He STABS the groom, then slaughters the bride! He then jumps through a wall, but travels through some kind of portal into a classroom. He awkwardly walks out, and is confronted by dozens of ****heads in the halls. Needless to say, they are promptly murdered.
Also, IZO kills some monks, vampires, businessmen, vampire businessmen (I'm not making this up) gangsters, goons, and random people in the middle of a highway (he somehow traveled through time, or to a parallel world or some damn thing.) Long story short, IZO rules. It owns your soul.