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.
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.
Expect to carry your trash with you. Eating while walking is considered bad mannered. Sit down or at least stand in a place away from pedestrian traffic when enjoying a meal or snack.
Blowing your nose at the table, burping and audible munching are considered bad manners in Japan. On the other hand, it is considered good style to empty your dishes to the last grain of rice.
If you're walking inside your home while eating a plate of food, then yes it is considered rude, especially if there are guests in your home because you are supposed to be polite and respectful towards your houseguests and walking while eating instead of eating at the dining table is bad ettiequte.
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. This is related to one of the fundamental concepts in Japanese culture, mottainai, which is a feeling of regret at having wasted something.
Eating while walking outside is frowned upon in Japan. In fact, eating almost anywhere other than a designated eating area is frowned upon. If you've ever taken a stroll outside in Japan, you'll probably notice that nobody is eating anything. It's also very rare for the Japanese to walk outside holding coffees.
Pointing at people or things is considered rude in Japan. Instead of using a finger to point at something, the Japanese use a hand to gently wave at what they would like to indicate. When referring to themselves, people will use their forefinger to touch their nose instead of pointing at themselves.
Pointing at people or things is considered rude in Japan. Instead of using a finger to point at something, the Japanese use a hand to gently wave at what they would like to indicate. When referring to themselves, people will use their forefinger to touch their nose instead of pointing at themselves.
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.
Avoid things like tank tops, shorts, and mini-skirts. Opting for more conservative clothing is always a safe bet even if you don't plan to visit temples or shrines. It's also generally frowned upon for women to show cleavage. Clothing with offensive messages or designs.
Eating while walking in Japan is generally considered okay. There's also no cultural relevance that prohibits people from eating while walking. As long as you are following TPO guidelines, you should be good.
If you are not wearing socks, it is polite to bring a fresh pair of socks to wear after removing your outdoor shoes because entering someone's house barefoot is not considered well mannered, although acceptable in informal situations. Slippers can generally be worn anywhere except when entering rooms with tatami floor.
Prolonged eye contact (staring) is considered rude. Don't show affection, such as hugging or shoulder slapping, in public. Never beckon with your forefinger. The Japanese extend their right arm out in front, bending the wrist down, waving fingers.
Bowing is an essential part of Japanese custom to show respect, thanking, greeting or apology. In stead of shaking hands, we bow, and it depends on time and people how long and deep you bow.
Never point your chopsticks at another person, wave them in the air, or spear food with them. Don't stick your chopsticks into a bowl of rice, as this is reminiscent of a funeral rite. Don't pass food from chopsticks to chopsticks, as this too is reminiscent of a funeral rite.
In Japan (and in many Western countries), people make sure they blow-dry their hair before they go anywhere. This one is also an unspoken rule.
Society and culture
For example, a burping guest can be a sign to the host that the meal satisfied them and they are full. In Japan, burping during a meal is considered bad manners. Burping during a meal is also considered unacceptable in Western cultures, such as North America and Europe.
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.
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.
Eating while walking is a big no-no for most Japanese–even children enjoying an ice cream are often told to sit down before consuming food.
NOTE: The Japanese don't ever dress poorly. Their fashion may be off the wall, but they do it with Armani jeans and Gucci shirts. So I wouldn't wear jump-suits, sweats or gym shorts, unless it's just to chill out in your hotel room.
If you're exploring cities like Osaka, Kyoto, or Kobe, it's the general “stand right, walk left.” When in doubt, simply line up behind the next Japanese person in front of you!