It advertises itself as just 2.5 hours from Tokyo. It was formerly known as Koumi Re-Ex Ski Valley but changed its name in Sept 2022 to Chateraise Ski Valley Koumi.

You can check out there website in the link provided, however, as of the last time this page was updated, there was no English or second language mentioned.

The same operator, operates Charteraise Ski Valley Nobeyama (previoulsy known as Chateraise Ski Resort Yatsugatake).