I am from the USA with a MS in physics and I am very interested in the work of a professor at the University of Tokyo. I reached out to him to explain that my previous work involved his papers and I inquired if he was taking on any PhD students. Unfortunately, he replied with this:

"Dear SpectreMold,

Thank you for the message.

Very unfortunately, I cannot supervise any PhD student at my department due to regulations.

If you are interested in some short-term programs for PhD students in Japan, the following page could be useful

https://www.jsps.go.jp/english/e-fellow/index.html

In particular, "Summer Program” and/or "Short-term Program (PE)”  would be something you are looking for.

I hope that you will find a good opportunity in your PhD research.

Sincerely yours,

Professor"

I told my current advisor this and she said this was due to the political situation in Japan, and this is why we do not see many Japanese professors or students in our field. What does she mean by this? Is funding hard for Japanese researchers?