Snowshoeing you said?
Although this activity was still often belittled and snowshoers were the laughing stock of skiers, the popularity of this activity hasn't stopped growing. Japan makes no exception as more and more hikers find in it a continuity of their summer activity and some others leave ski resorts to step in the wild and enjoy winter atmosphere away from crowded slopes.
The combination of rainfall coming from the Pacific Ocean and cold wind coming from Siberia provide Japan with abundant snowfall which is of high quality. Also, if the Japanese Alps require Alpine skills in winter, other mountainous region of the country lend themselves to snowshoeing. With a softer relief, being more accessible, they also offer with their ski resorts and remote hot springs town, quantity of bases with all level trails to explore these areas. The north part of the Yatsugatake range and Oku-Nikkō where I went back in 2008 are perfect examples and they are just next-door to Tōkyō! (see http://www.tozai-trek.com/lang/en/2008/03/we-raquettes-kita-yatsugatake
The ones who are looking for a wilder or more solitary experience, should go further north to Tōhoku or Hokkaidō (http://www.tozai-trek.com/lang/en/2008/03/raid-raquette-hachimantai
When planning your snowshoe trip, try as much as possible to end it in a hot spring. Bathing in a rotenburo after a day walking in the snow is such a pleasure!
When snowshoeing you are exposed to an unpredictable danger : avalanches. So get properly equipped with a beacon, a probe and a shovel (each person of the party having all 3 of course) and get trained on how to use them. Although true everywhere in the world, when snowshoeing you need to be autonomous. But this is especially true in Japan as you shouldn't count on ski resorts patrol, rangers or rescue to dig you out. Most of them might have never seen a beacon! If in western countries there are professional mountain rescue teams, this is not common in Japan. You go there at your own risk. There are very few ski resorts with teams equipped and trained for such rescue. Anyway even if there were, remember that after 15 minutes the chances of survival of you mate buried in the snow drop to 30%.
The same applies to avalanche danger forecast. It barely exists in Japan even in Japanese! Dave Enright from Evergreen Outdoor
, member of the Canadian Avalanche Association, publish avalanche bulletin on his website for Hakuba ski resort but outside of that there are very few informations. So you purely rely on your experience.
If you are not confident enough, I recommend you to hire a professional guide. (I will be delighted to guide you; you can contact me through my home page : http://www.tozai-trek.com
Just one word about snowshoes. Japan is a mountainous country, so you should use snowshoes adapted to mountain terrain. In other words I don't recommend you to use the classical North-American snowshoes made of an aluminum pipe frame. Even though they are the most common in Japan, they are not adapted to the terrain. I recommend you to use European plastic frame snowshoes which have a much better grip and last longer. See http://www.tozai-trek.com/lang/en/2009/03/composite-vs-aluminum-snowshoes
for more details.
The author disclaim all responsibility or liability in case of any sort of accident cause by the usage of the informations in this article.