How to get to the Nash Hash site:

Driving: See MAP

Flying: If you are arriving at Narita or Haneda Airport, you can choose your own route to Shinjuku station by using the Japanese Traffic Guide or - the RECOMMENDED route is:
(From Narita - Keisei Express to Nippori / From Haneda - Tokyo Monorail to Hamamatsucho) - then change to Yamanote Line to Shinjuku Station - and go out West Exit for Bus.

THE BUS to "HIRANO": From Shinjuku St. West Exit, buses will be leaving at :
09:10 / 11:10 / 13:10 / 14:10 / 16:10 "Shinjuku" --- (2 hrs 20 min transit) to "Hirano"
(5 minutes walk to "Idomae Hotel" trail will be marked)
The fare to Hirano is 2,000 yen one way.

OR: you can choose an alternate route by Train and Bus:

Shinjuku Station (Chuo line) to Otsuki Station (90 minutes), then change to (Fujikyu line) bound for Fujiyoshida Station (50 minutes). Then bus ride to Lake Yamanaka by 25 minutes bus ride.

Shinjuku Station (Odakyu line) to Gotenba Station. Then 40 minutes bus ride to Lake Yamanaka.

From Tokyo Station (Tokaido Line) to Kozu Station (80 minutes). Then change to (JR Gotenba line) to Gotennba Station (60 minutes). Then 40 minutes bus ride to Lake Yamanaka.