Well, dig it, the vid clips I've sampled, including one I found here of a 100 japanese woman getting fucked in the same room was overbearing, to be polite. i mean, they sounded like someone was trying to pull their insides out. But then again, they could've been acting, I mean, not all women react that way 100% of the time. We see american/european porn starlettes being pounded the same way with the same kind of whimpering yet we tolerate it willingly.
But then again, someone made a good point; Japan, for all tents and purposes still remains a male dominated society in sex, and as such, some of the women feel obligated to appear submissive. It's a power play, not all sex could be that painful.