Women can give birth anytime and anywhere, without any restrictions, as long as they can give birth safely. So there are Kudou Shinichi, Shinzo Abe, Yamamoto XI and even 56 names. Japan is far more than such a name, and surnames such as Shinichi Inoue, Fujiichi Yamanaka, Tanaka and Matsushita all correspond to places. It means that these people were born in the mountains or fields or even beside wells, so they took these surnames directly.
It can be said that Japanese names will not be passed down from generation to generation, and most of them are named according to their own wishes. Even the names are simple, in the name of numbers. This is also because Japan's population was insufficient before World War II and could not meet the needs of national conscription. Women are responsible for giving birth, taking care of the family and raising children, while men should enlist in the army and go to war as long as they meet their age. So that when her husband died during the war, she found another partner to continue to have children, which is why there are so many surnames in Japan.
Now Japan still retains these bad traditions, and women still keep house as before. Men earn money to support their families. Although not all men are recruiting, some bad ideas still exist. Now Japan is still the same preference for boys, and women have no status.