[Starskysea]

Weeelll I am by no means an expert but you will be a gaijin in japan, and expected to make mistakes, so people won't be quite as offended by any mishaps you make. The trick is to use 'sumimasen' a lot (when bumping into people, asking for people to move, saying please/thank you, etc). Learn politeness formulas and make sure to use 'san' and 'kun' where appropriate. Also learn the gestures...for instance, the movement for when someone beckons you looks a lot like the western 'go away', and it can be extremely confusing.