Is public sex acceptable in japan?

Question:

I have seen a few videos where Japanese girls are forced to have sex with random men, mostly on a subway train or city-bus.. Is that for real ? Would that not constitute a crime, considering those young ladies seemed unwilling in most videos, (well at least in the beginning, then they seem to enjoy it-but thats not the question) or is it socially acceptable nowadays to have public sex in Japan ? Thanks

Answer:

i've also watched an american porn and 2 girls had sex in the bus.
does that mean sex in public is legal or acceptable in usa?
or moreover, is lesbian sex common in buses in usa?
ofcourse its porn. its staged so use common sense.