I am Japanese and I live in Japan. If you want, I could help you if you come to Japan (if you come near where I live). I only have one short touring experience, so I may not be much help, but I'll tell you what I know.


-Plane tickets costs vary depending on season, but I am guessing around $1000 to $5000 (New York - Tokyo). It usually costs more around summer vacation or new year. It costs much less around March and October. Yes, it sounds ridiculous, but that's how it is.
-stealth camping is not preferred in Japan in rural area such as park BUT if you go to police first and tell them the situation, it is very VERY unlikely that they will say no. Especially as a foreigner, I highly suggest no stealth camping.
-I am not sure how expensive it is, but very cheap ones are from $40 to $80. I highly suggest "Rider House". It is like a super cheap motel but they usually give little/no food, usually no mattress and a lot of tourists use this place for one night and the reason for its name. Costs ranges from $0 to $15. (see below).
-IT IS ABSOLUTELY FALSE THAT JAPANESE DON'T LIKE AMERICAN TOURISTS. Whoever spread that rumor is absolutely stupid and hates Japanese. Unless you act like a jerk, Japanese will likely help you if you ask for it.


I live in Japan, Hokkaido. More specifically Sapporo City. I am a college student and I am also willing to tour next summer around Hokkaido. I very much recommend touring in Hokkaido than the Honshuu area. There are several reasons to this:
-There are many Rider Houses in Hokkaido, much more than in any other area of Japan.
-It isn't overly hot in summer.
-Roads are wider than rest of the Japan roads.
-Overall is considered one of the best places to tour in Japan.
-I could help you.


Reply if you have more questions. Also, like other people says, bring enough money.