"Kantoku banzai!" is a very strange movie to see. Much like the "Adaptation", it is - in a way - a movie about itself being made.
Takeshi Kitano plays himself as a director who's trying to shoot movies in all possible genres but never really manages to do so. But much more than about the lack of success in those movies, "Kantoku banzai" seems to be about Kitano's being tired of all those genres with this movie eventually turning into a quite chaotic meddle of all previously presented genres. But contrary to the "Adaptation", "Kantoku banzai" doesn't try to put it all together into a coherent story so we're left with a bunch of very loosely connected clips ranging from regular slapstick comedy sketches (the karate scene is hilarious!!!) through slightly crazy scenes to some utterly insane and absurd brainstorming. That may be confusing when you try to make sense of the movie but I think it basically is what the movie is about - the director doing whatever he wants to.
This all would make for a really great movie, the only shame is that it sometimes tends to be long and gets a little boring, especially near the end.