sick. I'm going to Japan too this winter! It's a sweet country. Make sure to look for some ski deals in the Kanda area of Tokyo. Twins for 200 bucks by february!!!
Hakuba is a cool place (right by Nagano, where the Olympics were held at). There's like 7 mountains to choose from in that valley. For only 85 bucks, you can get a 2 day lift ticket that gives you access to all 7 mountains in the valley. http://www.vill.hakuba.nagano.jp/e/ski/index.html
If you don't mind flying all the way up to Sapporo *where they get the most snow, there's a good resort called Niseko. It's kind of like the ghetto version of whistler in Japan. Lots of Aussies hang out there and there is a pretty good party scene.
hope those links help.