What's up with the Japanese and their violence?
What's up indeed? Takashi Miike (Dead or Alive trilogy) is all about the ultra-graphic, ultra-vicious on-screen violence. Ichi the Killer is to violence as Teletubbies are to acid. Or something like that.

Here's the synopsis from Poker Industries:

When Yakuza boss Anjo mysteriously disappears, his right hand man Kakihara sets out to discover who is responsible. Kakihara is a brutal and sadistic weapon, and uses his detachment from social morality to his advantage, torturing and killing those he needs answers from. Meanwhile, in the shadowy streets, a bizarre individual named Jijii has been manipulating Ichi, an unbalanced killer in a superhero costume, for his own needs. When Kakihari learns of the urban legend of Ichi, he sets out to find him, hoping that he can deliver the pain he desires.

On the web: Ichi the Killer on DVD at Poker Industries