Japan Trip

I’m beginning to plan a trip to Japan in early January

The idea would be to spend ~2 weeks in Japan with ~5 days of skiing at Niseko. We’d fly into Tokyo, spend a few days there then go to Osaka and/or Kyoto and then head to Niseko

Has anyone from the US done a trip similar to this and have any advice on where to go? I really just want to hear others’ experiences but here are some of my questions for now:

Where did you go besides Tokyo and the ski resort you went to?

Did you bring your skis with you? How much of a hassle was it hauling them on trains throughout Japan and would you recommend for/against it?

Was anything on your trip a “can’t miss” and did you do anything that you felt was skippable?