If you do one thing in Japan, let it be this: Visit Yamanashi Prefecture in fall. Why? The view of Mt. Fuji is spectacularly accented by the deep reds, yellows, and browns of the autumn colors.
It was my second time visiting the Katsunuma area, as well as going for a hike up Mt. Daibosatasu. The onsens (hot spring baths), wine, and mountain views are a big draw to Yamanashi, but the view of Fuji on a clear day is pure magic. These photos were taken from the top of Daibosatsu, which is approximately 2000 meters above sea level.