In ancient times, Japan was very keen to learn from China's culture, but it is very respectable that when Japan absorbed China and even Western culture, it could learn from other cultures while ensuring its own cultural independence. The Japanese sent envoys to China during the Eastern Han Dynasty. When Japanese envoys came to China, they found that the national strength was strong and the people lived and worked in peace and contentment, so they worshipped China. After returning to Japan, the king of Japan learned the news immediately. The King of Japan was also smart and immediately sent learners to China to study culture. This situation lasted until the Tang Dynasty, and it was particularly prosperous. Because of the peace and prosperity of the country and the people during the reign of Emperor Taizong, the economy, culture and politics were at a very developed level, and even many foreigners were willing to settle in China. At this time, the Japanese sent more scholars to study in China and absorbed China's excellent culture crazily. They even copied it directly to their own country without processing, and it also spread to Japan with the surname culture of China.
At the beginning, not everyone in Japan could have a surname. Generally, only nobles were qualified to have a surname. In ancient Japan, there were also levels. Like Japanese civilians, they all have no names. Therefore, because there were many Japanese nobles before, but few surnames, the rate of duplicate names was high. Only then, Japan began to learn Chinese surname culture and began to improve.
Later, Japan was impacted by western culture, and Emperor Meiji immediately began to order reforms and learn advanced western culture. In history, this kind of learning was called Meiji Restoration, and one of the reform measures was about Japanese surnames, so the Japanese emperor ordered every Japanese national to have his own surname, which made those at the bottom of society suffer a lot. Because their cultural level is not high, they can't take their surnames casually, so they directly use their place names as surnames. For example, those who live by the river are called windows, those who live by the mountain are called mountain passes, and those who live by the well are called inoue. Therefore, there are various surnames in Japan, resulting in nearly100000 surnames.