I've been skiing there three times, each time at the end of the season. I usually go to Hakuba (a valley with multiple ski areas around it in the Nagano region). Hakuba-Goryu has good runs with some rails and tables too. Charmante, north of there along the northwest coast of the main island, has deep pow and some terrain features as well. For the most part, resorts have some terrain features to play on. and lots of bumps.
The website for Hakuba-Goryu is here:
Hakuba 47 is another cool resort connected to Hakuba-Goryu. Here's their site:
Here's some water rampage at Hakuba-Goryu, open around the start of May: