I didn’t see any past participants that were not Japanese, but I also did not see anything explicitly stating only nationals could apply. It might be worth checking out more in detail if you’re interested in traditional culture.  The website is in Japanese only.

—

The Pola Foundation for the Promotion of Traditional Japanese Culture is a corporate foundation which aims to foster and promote the development of Japanese traditional culture. The Foundation offers assistance to young artists engaged in traditional Japanese cultural activities.

See more information at:

http://www.polaculture.or.jp/promotion/polaaward.html