UPDATED with information from Wes Lang, editor of Hiking in Japan.
by site editor Rick McCharles
If you were to plan a hiking vacation in Japan, here’s my advice.
First, get a copy of Lonely Planet Hiking in Japan, the best guidebook in English.
Plan your itinerary scheduling more time than you expect getting to and from trailhead. (It’s easy to miss a bus connection and get stuck overnight somewhere.)
You’ll almost always lose a day due to bad weather.
An ideal trip, in my opinion, would include these 4 routes:
1) Tate-Yama to Kamikochi (6 to 10 days)
“Hike the length of the North Alps — top hike in Japan!
2) Daisetzu-zan Grand Traverse (4-7 days)
The ultimate long hike across the roof of Hokkaido.
3) Kita-dake to Huiri-dake (2-10 days depending on route)
Rough and remote traverse the length of the South Alps
* Mt Fuji is a must too, of course.
A wise man climbs Mt Fuji …
To do all of those you should be there July – September. … you can get away with going in June if you’ve got a pair of light crampons. May if you’ve got skis.
Questions? Suggestions?
If you’ve hiked Japan, what do you think?
besthike.com 
Thanks for the tips. I have no plans to travel to Japan but if the opportunity presents itself, it is always good to benefit from experience. From my own perspective, the photographs you provided from hiking in Iceland would take precedence. Stark, wide-open wilderness has a very peaceful appeal. Thanks for sharing your experience.
Hello Rick,
I want to do the hikes you recommended next summer. Why didn’t things go well for you? Thanks, Ron Strickland (ronstrickland dot com)
Excellent, Ron.
I’ll email you.
Hey Rick, my name is Dan. I am in Sendai right now and I have a 3 day weekend next week. What is the best possible hike/adventure you can recommend? It can be straight backpacking or a hike/onsen/small mountain village kind of thing. I can travel there by bus or train overnight so not too far away (like not up to Hokkaido or past Kyoto/Nagoya). I am will to travel farther North (but not Hokkaido). What should I do? You can email me at dan.telsey@gmail.com. Thanks.
Sorry Daniel. I don’t know the area well enough to make a recommendation.
You’ll need get some LOCAL info.
I will be in Japan in October, can you please recommend me some short hikes that just take a few hours to 1 or 2 days ?
This L.P. guide is not available here.
Sorry Stanley. I’m not really expert in short walks Japan.
Major bookstores in Japan will carry the Lonely Planet for sure. You can pick it up there.