So what is it about skiing in Japan that has devotees clambering to return again and again? It would be easy to repeat the (possibly apocryphal) quote from the one-time New England skiing supremo Les Otten: "It's the snow, stupid" To which one could add: "It's not called Jap Pow for nothing!"
The powder in Hokkaido is indeed plentiful, light and deep. This is because cold, snow-bearing winds blow in from Siberia in huge quantities, so that Hokkaido is swamped with it every winter.
The birch-fronded volcanic terrain in many Japanese ski areas can be intriguingly different from the Alps or the Rockies: there are little cliffs with deep, soft landings, hidden groves of gnarled birch trees, and untracked pockets packed with fresh powder which are rarely skied. Skiing off-piste is still something of a mystery for many Japanese.
But it's not just Hokkaido. The main island of Honshu has excellent skiing in the Hakuba Valley, which, thanks to the 1998 Nagano Winter Olympics was the first Japanese ski region to seep into the consciousness of Western skiers. Although Hokkaido later became the focus of Japanese skiing because of its legendary powder, the terrain at the Hakuba resorts - especially Happo One and Shiga Kogen, a snowy patchwork-quilt network of some 20 "resortlets" - have a much more alpine flavour. The Tsugaike Ridge mountains, which reach almost 10,000 feet, are almost as impressive as their counterparts in the Alps.
Depending on which guide book you read, Japan has between 600 and 700 ski resorts (it once had more than 800 - but its troubled economy has led to a number of closures) and between 12 and 18 million skiers:
Furano is nicknamed "the belly button of Hokkaido" because of its central position in a wide, flat valley in the centre of the island, and has magnificent views of Daisetsuzan-kokuritsukoen, Japan's largest national park. The name means Great Snowy Mountain, an apt description of the 15 peaks of more than 2000 metres. In the local Ainu language the name translates to "playground of the gods".
Although there is a traditional Japanese reluctance to sanction off-piste skiing, more and more resorts are now allowing it, if not directly encouraging it. The "old" culture is neatly illustrated by the most challenging "in bounds" run in Furano - Kuma Otoshi (roughly translated as Bear Drop), at the top of the Kitanomine Gondola. It's a long, rugged off-piste run which makes a welcome change from the groomed runs to which the vast majority of skiers and snowboarders are normally confined. But when I was last there, they could only ski it for 10 minutes, at special times, twice a day.
One Canadian instructor I skied with there explained: "The local thinking is that it's so steep that even a bear would tumble down the hill. When they open the run for a 10-minute period, one patroller sits at the top of the ridge and another sits over to the left and they actually try to count all the skiers and make sure everyone makes it off the run. If there were a problem, the patrol would have a good idea of how many people were involved and be able to offer immediate assistance."
These days more and more Hokkaido resorts have embraced the roller-coaster powder culture, such as Niseko, which includes Hirafu, Annupuri and Hanazono ski areas. Niseko was transformed and brought to the skiing world's attention by Australians and Americans determined to ski among the trees. On Hokkaido's highest peak, Asahidake, you can ski off-piste on the flanks of a volcano with steaming fumeroles. Many resorts, including Furano, have exciting night skiing.
One of my favourite areas is Japan's oldest ski resort, Nozawa Onsen, which is as famous for its hot springs as its slopes. A bullet train ride from Tokyo, it's a traditional village of cobblestone streets, with no fewer than thirteen public onsens (hot springs).
There is certainly major progress at the heart of county's "thou shalt not ski off-piste" mentality. But either way, it's not just the excellent skiing that makes Japan such an attractive proposition. Says Andrea Selig, a product manager at Brighton-based Ski Safari (which recently celebrated its 20th anniversary) and specialises in ski holidays in Japan: "The Japanese culture makes up huge part of any skiing trip there. If you like trains, you'll be in your element, with lightning-fast bullet trains whisking you to Tokyo or Kyoto, the ancient capital, and beyond. The food is fantastic (it helps it you like sea food!) but even if you don't - from miso soup to katsu curry - the cuisine is far more varied than you can imagine. You'll also find izakayas (Japanese pubs) and ryokans (traditional inns) in every resort and, relaxing in the steamy onsens (hot springs) quickly becomes part of the daily après ritual."