Visited Mt. Jeans in late December, 2008, on the day after a snow storm. I think it may even have been their first or second official day open of the season, due to a late start waiting for snow that year. It was a beautiful, sunny day.
The resort is very easy to get to by car, just 20+ minutes off the Tohoku Expressway. Quicker to get to than Hunter or Edelweiss even if coming from the south, despite being a bit further up the expressway, due to greater proximity to same. We got there mid-morning, and had to park in a far parking lot (1,000 yen), from which there was a circulating bus down to the ticket area.
The ski area is on the small side, consisting mainly of two reasonably long runs coming off the gondola (one expert and one intermediate, though the expert run was closed the day we were there), with a fast quad going up parallel about half as far as the gondola, a pair lift to the left-hand side of the gondola serving a beginner's slope, and two pair lifts to the right of the gondola, one serving a mogul bahn and one a somewhat isolated, though scenic, intermediate course off to the far right. There is also a little lift off to the upper right of the top of the gondola, which seems to be mostly for private or school bookings, and was not running that day. And that's pretty much it. It almost feels as though half of the ski area never got built; surely they wouldn't have put in a gondola without grander plans in mind? But I don't know anything about the history of this place.
Incidentally, off to the right of Mt. Jeans, across the prefectural boundary in Fukushima, are the remains of another ski area which went out of business a few years ago.
That said, what they do have is not bad. The long intermediate course off the gondola features several grade changes, as does the fork connecting it to the beginner's run, which provide some entertainment. (Though the steeper bits got iced up by the end of the day from side-slippers.) The start of the run is a pretty tree-lined chute, widening gradually towards the bottom of the mountain. The connector from there to the beginners slope has some lips (probably edges of a summer access road) that can be taken as small jumps if bombing the run. Views from the top of the gondola, and even from the fast quad and the semi-orphaned far-right double, are also very nice.
If a pure beginner or in the company of one, be aware that there is only one course that is truly novice level, the rest being intermediate. For that matter, can't say anything about the expert-level offerings, since the one expert-labeled course was closed. Conversely, intermediates are well-catered for.
Lift lines were never more than a few minutes, despite being relatively busy.