I went skiing in Japan last winter and went to Hokkaido in the north to a resort called 'Niseko'. There was awesome powder snow there and many snowboarders. Next time I go back I think I'd like to try snowboarding - are there some recommended places in Japan?
If you are just starting out snowboarding then there are plenty of good options. One great place to check out would be around Nagano (on the island of Honshu, easily accessible being about 2 1/2 away from Tokyo by train). Nagano is where snowboarding first debuted as an olympic sport so there is plenty of great feel about it around the place. Personally I have spent some time on Mt. Hakuba (http://www.snowjapan.com/e/spotlight/hakuba-goryu.html), and I can tell you that catching the chairlift down over the halfpipe / snowpark and seeing all the great snowboarders playing down there was really amazing and made snowboarding all the more appealing. about 8 years ago
I have been skiing in Japan a few times including around Nagano in 2007. I think that Hakuba is more suited to intermediates and not so good for beginners. Getting there involves getting to Tokyo by the Narita Express, then a bullet train to Nagano and then a bus to Hakuba. I stayed at Ks House which was cheap and rather nice. http://kshouse.jp/hakuba-e/
There are a number of Onsens around which are an essential part of the experience. Whilst the exchange rate is pretty terrible now, it has been extremely cheap to stay and ski. Y4000 for a day pass and a little less per person accomodation, just a few minutes walk from a lift.
I have also been skiing in Ajigasawa in Aomori but its fairly hard to get to without local help. I think that skiing on Honshu rather than Hokkaido gives much more of a Japanese experience as you need to "self sufficiently" traval and eat where most of the people are Japanese.
Don't forget the JR East rail pass as it is expensive to travel within Japan. You need to buy it here before you go.
You can also use the Takkyubin service that will deliver your skis to the hotel/lodge overnight so that you don't have to lug them around on the bus and train. Its only $20 or $30 and so convenient.
Next time I go I am flying in to Tokyo and heading north to Yuzawa in Niigata. This is, of course, after visiting my favourite Tokyo spot, Akihabara..... about 8 years ago