I used to work for a Japanese company and that was about the only time in UK that I've been able to find high class Japanese escorts of the type you might find in mainland Japan. I have very occasionally met a SP who happens to be Japanese but often it's just a SP who looks Japanese and speaks Japanese or has mixed heritage.
Don't get me wrong, some of these have been excellent.
But nine times out of ten when I see "Japanese massage/escort" recently advertised at the cheaper end of the market and I ask some questions in very simple, modern Japanese I'm usually disappointed.