Before starting to eat a meal, saying itadakimasu, a polite phrase meaning "I receive this food", is a way to show gratitude towards the person that prepared the meal. This can be done in a praying motion, which is gathering both hands together, or more simply, by bowing the head.
When eating from shared dishes (as it is commonly done at some restaurants such as izakaya), it is polite to use the opposite end of your chopsticks or dedicated serving chopsticks for moving food to your own dish. Blowing your nose at the table, burping and audible munching are considered bad manners in Japan.
Before eating a meal, people clap their hands together and say itadakimasu and then repeat the same action but with the phrase gochisousama deshita at the end of a meal. This is to show respect to the host, the chef, or to whomever you are eating with. It also shows your appreciation for the food.
Before eating, Japanese people say "itadakimasu," a polite phrase meaning "I receive this food." This expresses thanks to whoever worked to prepare the food in the meal.
Many Japanese people believe it is poor manners to walk or do other physical activities while eating because it means you're not appreciating your food properly. For some, this belief has its roots in World War II, when food was scarce and it was something to be treasured, not treated casually.
Always finish your meal!
The Japanese consider it rude to leave food on your plate, and even more so to order more food when you haven't finished everything you've already got.
It is rude to make noise while eating as here in the U.S. but there are a few notable exceptions: when you eat Japanese noodles (soba, udon, ramen, somen, whatever), when you have miso soup.
It's rare to see someone in Japan chewing on a piece while talking to a friend, and you'll pretty much never see service workers or other people who are on the clock and expect to be in customers' line of sight chewing gum either.
Sometimes, this rule is conflated with a Japanese one that has to do with slurping. At restaurants in Japan, it's considered proper to slurp noodles while eating. However, it is not polite in Japan to burp, nor is it polite in China to slurp.
Don't leave food behind. It's considered bad manners to leave even grains of rice behind, so be sure to clean your plate! If there are some foods you cannot eat, ask to have them left out of the dish.
Sitting upright on the floor is common in many situations in Japan. For example, meals are traditionally held on a tatami floor around a low table. Sitting on the floor is also customary during the tea ceremony and other traditional events.
After finishing the meal
If you use disposable chopsticks (waribashi), put them back in the chopstick bag and fold over the end of the bag so that they can know you have finished the meal. If the tips of the chopsticks are dirty, wipe them clean using paper or Kaishi.
Table manners in Australia are Continental, meaning that the fork goes in the left hand and the knife goes in the right. In some cultures, it is considered polite to leave a little food on your plate, but Australia is not one of those cultures. Feel free to finish your meal.
Bowing (お辞儀, o-jigi) is probably the feature of Japanese etiquette that is best known outside Japan. Bowing is extremely important: although children normally begin learning how to bow at a very young age, companies commonly train their employees precisely how they are to bow.
You'll be given chopsticks with your meal, but if you're not comfortable using them, it's fine to ask for a fork. That said, don't be afraid to try: it will show your guest that you're a good sport. It's also perfectly acceptable to eat sushi with your fingers, but sashimi should be enjoyed with chopsticks or a fork.
The Japanese are unfailingly polite. Usually very helpful. (To be fair, the odds of them inviting an unknown fellow Japanese for a cuppa are also ... Smiling is fine even though it is not customary in Japan.
In Japan, crossing one's legs is seen as disrespectful. It is because when you do this you show the bottom of your feet to guests, and since they have picked up dirt, you are showing that dirt to your guests. This makes for very bad business relations.
Never hugging or kissing
In Japan, touching another person's body is considered rude, even with friends or family. Hugging and kissing are mostly for couples.
Instead, you may bring the bowl close to your mouth and drink it. For soup served in larger bowls — often containing noodles such as ramen, soba and udon — use the spoon provided for the broth. When eating the noodles, slurp away! Loud slurping may be rude in the U.S., but in Japan it is considered rude not to slurp.
This means that many Japanese tend to remain silent during a conversation, until there is an opening to speak. Sometimes, silence is intentional to allow people time to think about the discussion. Silence is often understood as reflecting politeness and respect.
Slurping is a sign of appreciation
In Japanese culture slurping your noodles shows how MUCH you are enjoying your meal. The slurping process also cools down the noodles and enhances flavors, so don't feel uncomfortable and just slurp it!
Another rule when eating with chopsticks in Japan is that one should avoid placing them in an “X” shape. It is said that crossed chopsticks represent death itself in China. While Japan may not associate this practice with death, it is still generally considered bad manners to cross your chopsticks.
Walking and eating in Japan
Japanese tend not to eat while walking along or standing around on the street. However, it is acceptable to drink while standing aside a vending machine. Eating and drinking on local trains, but not long distance express trains, is also frowned upon.
Hara Hachi Bu: Stop Eating When You're 80% Full
If you've ever been lucky enough to eat with an Okinawan elder, you've invariably heard them intone this Confucian-inspired adage before beginning the meal: hara hachi bu — a reminder to stop eating when their stomachs are 80 percent full.