Why are Japanese names more than four words?

Japanese names are more than four words, starting with the origin of names.

Japanese people didn't have a name before, let alone a surname. Later, in order to manage people, there must be a household registration system, and people should have names.

However, most ordinary people have no education, so it is very troublesome to name themselves and their families suddenly, and there is no way to start. So most people basically call everything they see. Those who have fields at home are generally called fields, those who have wells are called wells, those who make clothes at home are called Hattori, and those who like animals are called Bai Niao, all of which have beautiful meanings. Sun, moon and stars can all be surnames.

But surnames have taken up two or more words, so there are not many words left for names. Everyone wants to give his name a nice and beautiful meaning, but one word can't express all the meanings clearly, so he usually takes two or more words. Some people's own surnames are several words, and with their first names, there must be more than four words.