I don't think it's that much of an outrageous claim, plenty of our fellow countrymen works at local regional branches and English wings of China-owned companies these days. It doesn't take much stretch from there to imagine some of them moving to near their HQ.
It's annoying that sometimes people thinks there has to be basic mutual intelligibility between Chinese and Japanese languages against the reality that there's none, but this is not about that at all. Chill.
Microsoft paid more in Beijing than Tokyo while I was there, it turns out even experienced programmers in Tokyo don’t make $200k/year. Especially if you have a PhD or research in a hot field, you can get a pretty good job in richer Chinese cities. But an apartment is probably more expensive to rent in Beijing, and definitely in Shanghai, than it is in much of Tokyo, so there are trade offs.
It's true that rents in Tokyo are expensive, but Kawasaki or Adachi, where the commute takes about 20 minutes, are cheap.
I don't know about the salary, but I checked X or blog and it seems that some are work in the US headquarters, but none in Beijing.
Anyway, when are you there? It looks you are talking in 2010.
Could you tell me more about that?