Most protection groups seemingly ignore that reality, at least when they campaign for the issue. I haven't read the UN article, but Amnesty International noted that on a good day, this sort of crime is a social and legal minefield.

There's a significant difference of power which means it's easier to attempt to hide it or at the very minimum bluff it out.

The real question is though - is that tendency so much bigger in Japan to represent such a skewered reporting statistic?

I'd be more inclined to look at the fact that family nudity (Skinship, and the like) would mean that the Japanese mindset sees more potential for it happening, but on the flip side, it also means they have a lot of cultural norms around it, so it's a lot less likely to happen.

Well, barring the usual psychopaths, but we're talking statistically, not the exaggerated stuff that most places push for better news.