Since I started this thread I've actually gone to Japan a couple of times. I can hardly speak any Japanese and I can't read any at all, so I was a complete tourist noob in that regard. I did try to do some basic research on how to not embarrass myself; simple things like not talking on a cellphone while on a train or blowing your nose in public. I've read online that Tokyo is the least friendly city for foreigners, and that's where I was both times. I was traveling alone, so no guide or anything, but I did rent a Japanese iPhone for GPS nav and to look stuff up online.
In my experience on the whole people in Japan were much more open to foreigners than I would expect people in my home country (america) to be. It can be difficult to tell in some cases what someone is really thinking since people there are so, so polite, but even given that, there were people clearly going well out of their way to be nice.
Sure (sometimes) in lines or crowds I seemed to have a larger personal-space-bubble than everyone else, but then again there were times where people seemed to go out of their way to be in my vicinity as well.
I've been trying to remember a single foreigner-unfriendly moment during my trips but I honestly can't think of any. The best I can do is I saw another tourist outside a concert trying to get directions to somewhere by stopping random teenagers and just talking to them in english. She was a bit frantic/insistent too, so I'm sure she wasn't coming across as the most sane.
Most of the teenagers clearly couldn't tell what she was saying and would brush her off. I can't say I'd expect differently in any other country in the world. If you need directions your best bet is to talk to the staff people right there, and I don't think it's too much to expect a tourist to at least learn how to say "Excuse me" and "Sorry, I can't understand Japanese". I know I said that hundreds of times, and it at least lets people know what is going on.
Anyways, this is all off track, the point is if this is the worst thing I can come up with from my trips to Japan, it's really not that bad.
I was asked for my passport (very politely) while sitting at the airport, but I was never stopped by the police or anything while walking around, even when going down small suburb residential streets the GPS led me down (at night, well outside the usual city tourist areas) on the way to a concert at a small college.
