Upvote:2
As for maps, you can always make use of OpenStreetMaps or GoogleMaps. Given that you have mobile internet with you.
Most public campsites and trails have map signboards and/or pamphlets.
If there is no a tourist map of all the Japan are there any maps at least of some areas?
If you happen to live in Tokyo, you can grab a map of Tokyo and a tourist brochure (containing very nifty tips of all the cool places to visit) in the Tokyo Metropolitan Government Building.