I know I'm probably breaking a rule by doing this, but since it so well applies, in the link i have in my signature there is a customs catagory. I live there and have broken plenty of the rules, so I'm writing about them now. It's still a work in progress but there's definitely some content up. Check it out if you like. (Sorry for the self-advertisement, but it applies. If it's a problem let me know and I'll delete it.)
Not sure if this is a faux pas, but I have noticed that I get stink-eyed when I eat outside (hell, I bought mitarashi dango from 7-11 and I had nowhere to eat it). Does anyone know if this is rude?
For the older generation, eating is a more sacred act than it is for younger people, simply because many of them lived in a time when every grain of rice was a true gift. Therefore eating and walking is considered rude by older people.