I once saw a quite well made Japanese porn and after that the making-of (because of some promised extra material)... I gotta tell you, these girls were actually learning their scripts and reading voice-overs, the staff was talking productively (and not just "and then you come from behind...and bam bam...ram your dick in her ass....while you....you start eating her box...") and a load of other stuff was going on. I was shocked and appalled by the seriousness and respectability. :dunno:
Of course that's not the case in every Japanese porn movie....there's also the multiple-alien-tentacle-impailment-while-leather-bondaged-and-throat-gagged-till-puking-whilst-being-ass-sniffed-and-earmuffed-by-a-pink-koala-porn.