NISEKO, Japan—This town in the snowy northern island of Hokkaido is emerging as Asia’s answer to Aspen and St. Moritz, drawing billionaires to its slopes and, soon, global hotel brands like Park Hyatt, Ritz-Carlton and Aman.

Resorts in and around Niseko are luring winter-sports lovers from Asia and North America who enjoy the powdery snow of northern Japan by day and the warm sake at night. The inexpensive inns with futons and shared bathrooms have given way to $400 hotel rooms and condominiums priced as high as $10 million.

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