Rules in japanese dinning

Some rules to remember:
Never pass food to someone using chopsticks. This act parallels passing cremated bones of a deceased relative at a Japanese funeral. If you must share food, pass them the plate so that they can pick from it instead.
If you take food from a shared plate (such as in the above situation), use the reverse ends of your chopsticks rather than the ends which go in your mouth.
Never bite into a piece of food and then replace the other half on your plate. Once you have picked something up you should eat all of it.
When not using your chopsticks, you should place them in front of you, parallel to the edge of the sushi bar, with the narrow ends in the provided hashi oki; never place them directly on the bar.
Never leave rice after a meal. Leaving any kind of food is considered rude, but leaving rice is especially so.
Never smoke in a sushi bar, it obscures the delicate flavours of the fish for everyone else. Ashtrays will likely be provided in many sushi bars (especially in Europe and America) but to use them is dismissive of the efforts of the chef.
Never expect the chef to handle money, another employee will settle the bill for you. People who handle the food never touch the money.
Do not ask for knives. This would imply that the food is so tough it can't be properly eaten without them.
Don't make wasabi soup with your soy sauce! Sushi Chef's cringe at this spectacle that Americans often make. Wasabi paralyzes your palette and will hide the subtle flavors that fish has when eaten raw.