First of all, Japan is a country that pays great attention to privacy, so when traveling, if you want to take pictures in private places or shoot local people, you must ask and observe in advance. Because some private places will have signs prohibiting taking pictures, tourists will face heavy penalties for taking pictures at will. Moreover, if the other person doesn't want to be photographed, it is very impolite and will make the Japanese feel offended.
In particular, if you put the completed photos on social platforms or public places without the permission of the people at that time, it will infringe on the rights and interests of the people at that time. If the other party is unwilling, it is likely to face prosecution. This must be noted.
Secondly, Japan is a place that pays great attention to etiquette, so it is forbidden to make a scene at home. Some young people like to hold parties in Japan, so they will be very noisy. Japanese people especially like to laugh loudly to express their emotions, but only in China did they know that even in places where people come and go, such as trams and railway stations, they would feel as quiet as in a library. On the tram, the phone doesn't ring, and most of them are silent.
So once the room is noisy, it will affect the life of the Japanese, and they will complain to the police. Calling the police abroad is also a very troublesome thing.
In addition, living in Japan, someone knocks at the door, so don't open it casually. It is likely to be entangled by NHK and charge you money. But even if the government or the police come to the door, the Japanese government will call in advance to make an appointment and then come back. So don't open the door as long as someone you don't know knocks. Don't think that Japanese people are polite and have no bad people. Stay alert wherever you are.
In particular, NHK staff are all in suits and ties now, just to mislead some people who are not familiar with Japan and want to charge.