Keep your hands out of your pockets while speaking to someone. Doing so shows boredom or lack of interest.
Blowing your nose in public is generally frowned upon in Japanese etiquette. Excuse yourself to the toilet or go outside to clear your nose.
Avoid pointing at people with a finger to make a point. Pointing, whether with fingers or chopsticks, is considered especially rude.
The numbers “4″ and “9″ are considered unlucky in Japanese culture. The word for four (shi) is the same as the word for death, while the word for nine (ku) can mean suffering. Avoid giving gifts or anything else in sets of four or nine.
Tipping is not customary in Japan, and is sometimes considered rude.