If you know anything about adult videos, you should know that Japanese Pornography is censored, in that gentiles are blurred out.
Know, I know many people like to complain about this aspect about Japanese pornography, but, here's my opinion on it.
Because there is some censorship, Japanese Porn doesn't need to concentrate like western porn on endless minutes of extreme close up shots of some guy's nad pounding away. If that's what you're into, hey the more power to you.
But, when I'm watching some AV, I want to see the actress taking it, I want to see the action as a whole, and I don't want to spend most of the video watching an extreme close up of some guy's nad pounding away.
In Japanese pornography since they can't have super extreme up close shots without it looking like just a big blur, they concentrate more on the action, wide to medium shots where you can see the girl getting banged and the action as a whole. Also Japanese pornography has some interesting developments because of the censorship, things like Japanese Bukkake have arisen, and have also transferred over to western pornography as well.