Interesting to see if someone can answer this one.
I guess it's a big national park covering 1250 Square Kilometers and spreads over 4 prefectures of Yamanashi,Saitama, Nagano, and Tokyo There is a lot of info on Google about it, but I did not see any GPS listings?
This is the GPS cordinates for the mountain lodge (Higashizawa Sansou) in Nishizawakeikoku. It is from a list of mountain climbing points compiled by a group of hikers. http://www.interq.or.jp/horse/madoka/tozan/gps.htm