Ichi the Killer is old news. The movie's been out for over two years, still badass though!
The movie's not all that weird really. It's about an urban loner slash closet schizophrenic who plays out his superhero fantasies by splattering Yakuzas with his special boots that house foot-long blades. The bad guy is one sick self-mutilating, sado-masochist who's slit blowholes into his cheeks. Not that weird if you ask me!
This movie is so over-the-top gory, it's a great way to relax for two hours. No doubt this movie was an inspiration for Kill Bill but it's like ten times gorier (dude get his skull sliced in half and thrown up against a wall and it slithers down).
If you like ultra-violent movies, check out Japanese cinema. Ichi the Killer, Versus and Battle Royale are great fun movies with the later being an important commentary about the pressures of academia in Japan and sensationilism of reality tv.