You would not get called out if you don’t follow them but it is better to know that we have these implicit rules. It might make your stay more enjoyable.
1,Stand on the left side of the escalator in Tokyo.

There are various theories, but it is said that the reason why many parts of Japan drive on the left side of the road has something to do with the fact that samurai used to carry their swords under their left arm. This rule was established to avoid the sheath of a sword clashing with another person’s sheath. It is said that, in order to accommodate the large number of people coming to Japan from abroad for the 1970 Osaka World’s Fair, escalators were designed to be right-standing and left-standing, which was the norm in Europe. In Hyogo and Nara, which are adjacent to Osaka, it is also right-standing and left-standing.
2, Wasabi is not dissolved in soy sauce.

Rules for eating sashimi. Take a small amount of wasabi with chopsticks, place it on top of the sashimi, dip a little in soy sauce from the soy sauce dish, and bring it to your mouth. This is to avoid dissolving the wasabi in the soy sauce and contaminating the soy sauce dish, and also to avoid the wasabi’s pungent taste and aroma from being lost.
3, Separate garbage into small groups.

Although there are more detailed rules in each area, the trash cans are different for burnable trash, non-burnable trash, cans, and bottles. Plastic bottles should be washed of their contents and the packages placed in the non-burnable trash, while plastic bottles should be placed in their own trash bins. The aim of this detailed separation is to reuse resources and reduce the amount of waste generated.
4, Do not step on the threshold of a shrine.

The threshold of a shrine should be crossed without stepping on it. There are various theories as to why this is so, including that stepping on the threshold causes damage to the building and that the threshold serves as a kind of boundary that prevents evil things.
5, Prepare stickers to cover the tattoo.

Although some people still have a negative image of tattoos, more and more people are becoming tolerant of them. Recently, more and more hot springs allow visitors to enter if they cover their tattoos with stickers, so it is convenient for those who have tattoos to prepare them in advance.
6, Prepare cash.

Credit cards and electronic money are accepted at almost all large commercial facilities and public transportation systems in Tokyo. However, even in the city center, some private stores only accept cash, so it is always a good idea to have cash on hand.
7, Do not speak loudly on trains.

In Japan, it is against manners to talk loudly or make phone calls in public places. In addition, even if they are moved by a movie theater or concert, they basically watch the show quietly without speaking loudly.
8, Punctuality.

Punctuality is an important rule in Japan, as evidenced by the fact that Tokyo trains are announced to apologize for even a few minutes’ delay. If you are running a little late for an appointment with an acquaintance or friend, or for a restaurant you have reserved, it is good manners to call in advance.
9, Soba (buckwheat noodles), udon (wheat noodles), and ramen (noodles) are allowed to be eaten noisily.

It is considered bad manners in foreign countries to eat noodles by slurping them noisily. This is not to say that it is better to make noise, but rather that it tastes better to eat with noise. Ramen, soba, and udon, which are considered a single item when both the noodles and the broth are combined, taste better when eaten after slurping, as the noodles and broth are intertwined.
10, Eat rice without leaving any leftovers.

Although recently there has been a growing trend to avoid leftovers, in China, leaving a little rice behind is a cultural way of expressing that one has had enough. On the other hand, in Japan, it has long been considered rude to leave rice for the person who cooked it or the farmer who grew the rice, so it is good manners to eat up all the rice that is offered to you. Of course, if you just can’t get enough to eat, don’t force it.