Biwako Valley is a small ski area with only 8 trails but it is actually pretty good in my opinion.
The entire ski area was open and there was a lot of snow in the trees. Yes the trails are short but if you read the mountain stats you shouldn't be surprised or disappointed. I went on a Friday so it wasn't very crowded. I'm sure the weekends would get very crowded though. There is only one annoying flat spot
At first I was a little worried about a lack of a good variety of terrain as there are only 12 trails. However, those concerns were alleviated as I took the lift up for the first run. The mountain actually has a great variety ranging from kind of steep, heavily moguled runs, fairly wide blues for carving, and a long cruising run for beginners. The expert runs all had moguls but you can take a break