People should know some chopstick etiquette. Don't hold your chopsticks up at your food, as this is rude behavior. Similarly, don't stick the tips of your chopsticks into your food, although some foods are not too easy to pick up with chopsticks, but chopsticks should not be used for sticking or shoveling food. Also don't use chopsticks to move plates around and don't use chopsticks to pass food around. One of the more serious offenses at the table is sticking chopsticks straight into a bowl of rice, which is a sign of death.
Japanese soups and other liquid dishes are to be sucked straight from the bowl. Although it is permissible to make smacking noises when eating noodles in Japan, such noises are not allowed when drinking soup, and it is drunk straight from the bowl, without a spoon, as the flavor of the soup is better savored this way.
When eating foods like tempura and sashimi, which require dipping, hold the soy sauce dish in one hand and pick up the food with chopsticks to dip it in the sauce. Instead of dipping the dish into the soy sauce on the large plate, pour the soy sauce into the small plate, a little at a time, to save it.
Unlike Western cuisine, Japanese food is relatively seldom dipped in sauce, making it difficult to taste the richness of the sauce. If necessary, Japanese people often pour soy sauce over their food, as Westerners do, and eat as much as they can before finishing their bowl of rice.
Japanese people are almost invisible as walkers, even when it comes to such harmless foods as ice cream. The Japanese consider that habit of eating while walking to be very unseemly. When people buy food or fast food, they often find a place to sit down and finish eating.
Don't refill your glass yourself; someone else will do that for you. Your job is not to fill your own glass, but the glass of the person sitting next to you. Doing so facilitates solidarity and promotes the formation of social groups, whether among friends or coworkers.
The general atmosphere of a normal Japanese pub is casual and relaxed, with fellow patrons pouring beer for each other. If you're drinking with a group of people, you can't have your first drink until everyone raises their glasses and says "cheers".