Take it with a grain of salt because this is from a pharmaceutical group, but this page claims the average body temperature of the Japanese was 36.89°C 50 years ago and that it was 36.20°C as of 2009. http://www.sawai.co.jp/kenko-suishinka/illness/200909-02.htm...

Edit: although, that might as well be due to the aging population. That said, I have been told that my average (by France standards) temperature was "a little high".

Same here. I'm a white dude and normal for me is about one degree (F) below "average" - 97.5

I wonder if there's a diet component. When I lived in Japan, after a while my temperature was an average 0.3 degrees lower than it used to be before. It returned back to what it used to be before after leaving Japan and switching to a different diet