Though the resort is small, Kusatsu Onsen in Gunma Prefecture boasts one of the longest ski runs in Japan, at 8 kilometers (just under 5 miles). There is a free shuttle bus from the town to the slopes and ski lifts of Kusatsu Kokusai Ski Resort 草津国際 . The ski resort has a good ski school with ski and snowboard classes for all levels and equipment rentals.
Kusatsu Kokusai Ski Resort in Gunma Prefecture
The mountain itself is more suited for beginner and intermediate skiers, more advanced skiers may find it not as challenging. The onsens and excellent food in the area could entice all levels of skiers though!
For those who want to see the beauty of Mt. Shirane in winter at a slower pace, try a nature course with snowshoes or cross-country skis. Only about 3 hours from Tokyo, Kusatsu Kokusai Ski Resort is a good choice if you want to add outdoor activities to a busy trip to Japan. In summer the ropeway lift is operating to take hikers to the mountain top and there are quite a few of activities during the summer.
Website is only in Japanese: http://www.kusatsu-kokusai.com/
