I've been to Sky Valley twice now, both times the day after a big dump of snow. Once was nice and sunny, the other snowing with nil to little visibility. Both times it was a great resort to be at.
The base at Sky Valley is situated in a very narrow valley, to reach the lower lifts you have to walk though the base building. It's a two story building bottom floor has two changing rooms (male and female), rental area,
A pretty big mountain for Hyogo, Sky Valley/Hyper Bowl offers a little for everyone, but lacks any of those truly challenging runs for more advanced folks, at least in the proper course. There's decent areas for boarders to play on, including a half pipe, rails, kickers, and if there's enough snow, a quarter pipe.
My first time up, I was more or less a first year snowboarder and was still learning. The bunny courses at SV is tougher and narrower
Connected to Tohachi so you can ride both mountains, although Sky Valley has better snow, better terrain, longer runs and shorter lines. I still haven't been to Hachi Kogen/Hachi Kita so I can't copmare, but this replaces Kannabe's Nashiki Kogen as my top pick for Hyogo. On Sunday, Tohachi had a 15-20 minute line at the bottom whereas Sky had none. Off the peak there is some pretty good steeps with easy acess to trees