How's your skiing? Do you have any qualifications? There are a couple of people on here who work as instructors in Niseko. Most bars/restaurants/hotels in Niseko hire western staff. The first thing to do is to try and get yourself a working holiday visa. Then google is your friend, send out CVs and get on the phone!
Or, another alternative is teaching English. Base yourself in Sapporo where there are alot of job opportunities for English speakers. You won't get quite as much time in the hills but you'll earn well and will have a different experience to the standard ski town thing.
I've been in Hokkaido a little over 2 years now, feel free to PM if you want more info.
