Rusutsu is a sick spot. Lots of good safe tree skiing, and its a little less busy than Niseko. But it's no secret anymore and is getting busier every year. There are some good budget lodges at the base of Rusutsu but they get booked up quickly in January. The only other option is the expensive Rusutsu Resort hotels.
Maybe use Rusutsu as a base and travel to some of the other ski hills in the area for a bit of variety.
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