I happened to work near this resort for a day, so went skiing there on the following day - a Saturday. This website reported 85-100 cm of snow, which was plenty. The runs were prepared nicely, of course you won't find any difficult or particularly interesting runs there. It wasn't crowded, in many cases I could just go through to the seats without having to stop. The lifts are a bit outdated and slow, so the full price of the ticket seems to be a bit steep.
I stayed one night at the Lodge at the resort, so I got a discount one day ticket for 2300 Yen. Ski set rental was 3000 yen, but I didn't like the boots very much... they have boots with size up to 30cm, so don`t worry.
It is a bit difficult to get there if you don't have a car. The lodge has a pickup service from the bus stop at Kamisaibara, which seems to be the only way to get there. It is helpful if you can speak some Japanese to get around there. When staying at the lodge, you should be fine with Japanese food as well; there is no other restaurant that's open in the evening at the resort.
I had lots of fun that day and somehow liked this place, so if you happen to be in the area, I recommend visiting Onbara Kogen for one day.