Start talking about extreme cinema, and eventually the path turns to Japan. You've got Living Hell, the Guinea Pig series, Kichiku: Banquet of the Beasts, Audition ... need I go on? The French may do disturbing like no one's business, but the Japanese just take things one step further than anyone thought possible. Watch Mermaid in a Manhole and tell me different.
I believe the French do disturbing so well because that culture really understands the artistic power of film. Cinema is viewed as a form of art and is treated that way. When you are a filmmaker in a culture that holds the medium in which you work in such high regard, you have to passionately study what works. If you are making a horror film, you want it to be horrific. You need to know what works.
Japan is different.
Japanese culture is a lot like American culture in some respects. It is as repressive as it is extreme. When people are repressed, yet artistically free, you see those repressive aspects of society come out in the art. Japan has also looked to America for much of its film heritage. It should be no surprise then, that when a Japanese director decides to do a horror film (or full-on exploitation flick) that it takes the mainstays of the genre and ratchet them up a few notches. It's not enough that the mermaid oozes multi-colored pus. That pus is then used to paint pictures of her as she dies. It's not enough to torture someone with a stun gun. That gun has to be forced into a man's mouth and turned on over a filling.
When a society is repressed, the artistic spirit eventually comes out one way or another. In Japan you have graphic comics, vending machines dispensing soiled panties, and film. It seems hard to believe that a society that still operates on shame could do something Kichiku with its heads blown halfway off in gruesome detail, but it actually makes perfect sense. This is how that oppression from repression works its way out. The culture's fascination with American films guarantees they can pull it off. The only ironic thing is that the Japanese films aren't bigger here in America.
These theories also go a long way to explaining the Canadians ...
-Doug Brunell (America's Favorite Son)