Just follow a few simple rules about the dos and don'ts in Japan and you'll leave the country without having rubbed anyone the wrong way.
Do: Take off your shoes
Contrary to other cultures, the Japanese will not let you wear your shoes in their house. This rule also applies to other places, like temples, and in many cases even restaurants and pubs. This practice stems from a cultural phenomenon called "uchi-soto," which means "inside vs. outside". "Inside" is associated with comfort, purity and cleanliness, while to the Japanese, the "outside" is soiled, unknown, or even dangerous. This concept translates into all kinds of situations at any scale: indoors vs. outdoors, family vs. other people, Japan vs. the world. So whenever you enter a space, make sure to look out for signs that ask you to take off your shoes. And make sure to wear socks without holes! Also, if you suffer from cold feet, don't worry. Those people who make you take off your shoes usually also provide special slippers for indoor use.
This "rule" was very confusing to me the first time I came to Japan. In Germany, where I'm from, part of the conversation is to to look your counterpart in the eyes while talking. If you're not looking, you're not paying attention. But this rule only partially applies in Japan. Here, an important part of communication is to break eye-contact every once in a while. And when speaking to a superior, you're not to look into their eyes at all. Early on, I was told by a Japanese friend that the way I watched him while he spoke made him feel very uncomfortable. And that I should be careful because others might consider it creepy, suggestive, even flirty. "But what do you do in formal situations, it must certainly be rude to look at the ceiling or down at your feet the whole time? Especially in meetings or job interviews," I interrogated him. "We are taught to look at their tie or general neck area instead," was his answer.
Do: Follow the rules
Wherever you go in Japan, you are likely to run into signs telling you what to do, what not to do, and how to do things. Follow them or you'll have highly annoyed clerks, service personnel, police officers, or common people on the street pointing them out to you. Take a closer look at the behavior they promote and you'll notice that all of these guidelines are set up to remind people to be mindful of each other and keep the environment clean.
Don't: Touch anyone
Unless they invite you to... or you're on a crowded train and can't help it that your whole side is pushed into another person. The Japanese culture is not a very touchy-feely one, and even now public displays of affection of any kind are a rare sight. A common interaction for some cultures includes grabbing a friend's arm when making a joke, or hugging or even kissing someone goodbye. This kind of behavior is not common in Japan. However, if someone does extend their hand towards you, take it! They've probably read a blog article similar to this one and are showing cultural sensitivity on their part as well.
Slurping noises in a ramen shop or teishoku (set menu usually including miso soup, rice, and a side of greens) restaurant are to be expected. But don't think of this as bad manners! Japanese people slurp for a reason. First of all, the only things that are slurped in Japan are noodles (ramen, soba or udon) and soups. The reason behind this is that while slurping, they simultaneously inhale cold air, which cools down the hot noodles and broth they are currently eating. Slurping won't be easy the first time you try it, but it'll make your ramen experience that much more authentic. Tip: Don't close your mouth too much while slurping up noodles. You won't get any air in, and the noodles will spray the soup everywhere! And while we're on the topic of food...
Don't: Play with your chopsticks
Playing with your chopsticks is plain rude. Think about it: Imagine someone at a restaurant drumming on the table with their spoon, licking their knife or pointing around with their fork. You'd probably think that person was ill-behaved. Well, the same goes for chopsticks – no licking, no drumming, no pointing. However, Japan does have some culture-specific restrictions on chopstick wielding. Passing someone food from your chopsticks to theirs and sticking chopsticks into a bowl of rice are both acts associated with the dead. At a Japanese funeral, after a person is cremated, the family gathers around the ashes and together transports the dead person's bones into the urn by passing them from one person to the next with large chopsticks. And the chopsticks sticking out of your grub resemble incense stuck into a bowl of uncooked rice commonly placed in front of a Buddhist family memorial shrine.
Do: Tone it down
The Japanese have a time and place for being loud, and that's in a karaoke box or at an izakaya (pub). Anywhere else, they like to keep the volume down, mostly not to annoy each other. On public transportation and shuttle buses, at shrines and temples, at restaurants and cafes, and especially in hot springs – tone it down a little. Of course, that doesn't mean you can't talk at all in public places, but just remember to be mindful of others.
Don't: Tip your waiter
In many countries tipping somewhere between 10 and 20 percent when paying at a cafe, a restaurant, or for your taxi is the norm. But in Japan, tipping, in general, isn't a thing. The price you see is the price you pay. Even if the service was outstanding, your tip will most likely be refused. In some areas, a waiter or cab driver might even actually run after you to return your tip and say, "Sir/madam, you forgot your change!"
Do: Keep to the left
Japan is one of the few countries of the world where cars drive on the left. And, subsequently, humans keep to the left as well, walking in the streets, riding an escalator, standing in line. If you can make a habit of always staying left as well, you're likely to prevent running into someone. The only exception in all of Japan are the escalators in Osaka and the Kansai region. For some reason, people here stand on the right and pass on the left, and no one really knows why...
Don't: Stress out about the cultural dos and don'ts in Japan
To be honest, the Japanese won't expect you to know and follow all of their rules. If you do happen to do something differently (which is guaranteed in any foreign country you visit), they will simply blame it on your foreignness. So chill out, enjoy this great country and have a good time!