Not surprising that the Japanese men would have to pay to be in the film, they clearly were not porno stars by the look of them, and it is the nature of sex that men always pay for it, either by marriage, pursuing our community's favorite activity
, or by paying for the privilege to be in that move. I would be surprised, however, that the girls had to, or would be expected to pay for it. It seems to me that given the nature of girls, they would need some incentive to do something like that and one would simply take the fees from the boys and pay it to the girls.
Of course Japanese girls are a different animal
l, perhaps they would pay for it, but most girls will simply not pay money to have sex with a stranger.