Things not to do in Japan

Don't forget to take your shoes off if you go into a Japanese house. There will be a step up just inside the front door and everyone will take their shoes off.
(Shoes with laces are a nuisance in this situation so take slip on shoes)

Don't sit on a table. Don't put your shoes on a table or chair even in the train. If you have to stand on a chair to reach something take your shoes off first. If you have a problem with sweaty feet use a foot deodorant.

Don't try to bow. Just shake hands, most Japanese business men will expect you to do that. If you bow and bump heads with your Japanese partner, you will just have to apologise.

Sometimes Japanese business men spit in the street, get drunk etc. Don't be alarmed or show distaste.

Don't hug or kiss.

Don't call anyone by their first name and don't expect to be called by your first name.

Never shout either in anger or to get someone's attention.
Don't criticise anyone or anything directly.
Don't boast.
Don't ask or give opinions on politics, race, the war.

Silence is OK. Don't feel you have to talk to fill in the silences.

If you are treated or entertained and you are not going to see the person again, it is best to write a reply as quickly as possible with thanks for the occasion. A short note on hotel notepaper will do until you get back. It is not polite to leave a long gap before thanking someone. In the case where you see the person again, your first words to them should be thanks for the dinner / trip the other day.