A bit late with this, i see the original post was over a year ago, still...
I am very interested in this kind of easy going travelling, too, and since there is SO much wild countryside in Japan, (while there are dangerous wild bears and some boar, there are fewer human villains, so far) - I think a lot about 'wild terrain' and winter camping, (and the kind of 'car camping' described in this thread. ie in an ordinary car, not a specific 'camping car') - a way to travel which is acceptable in many parts of Europe, and which I have done many times without the smallest problem. I know that parking in Japan is quite severely restricted and I have seen few official 'public car parks' of the kind that are available around European towns and resorts etc.
In Japan there is plenty of fresh water, and basic food supplies are not at all expensive, good public baths and toilet facilities are readily available, countrywide.
Talking about it with Japanese people - is not easy (especially as i dont speak Japanese!) - there does seem to be a faint 'shock horror' response. Im not sure why, but have yet to find Japanese people who are willing to discuss their objections and how any problems are overcome.
Is there anyone who has camped in wild terrain on this list please? Who can add any opinions?
As for hostels, and cheap, basic ryokan, I have stayed in both, many times - and found the service, most often, with only one exception, truly excellent, high standards of cleanliness, and often better facilities than the more expensive hotels.(eg internet access and cooking facilities).
Tatami room and futon sleeping seems to me to be best and cleanest way to sleep, too.
I have no confidence in the fitted carpet, & thick western style mattresses - that cant be cleaned nearly so easily as a futon and bean pillow, on tatami.
I hope there will be more contributors to this thread who have experience and ideas how to travel in these very basic ways.
