2, familiar people call their surnames;
3. People who are very familiar call them by their first names;
4, a little more intimate can be called a nickname, such as XX sauce, which means nickname.
Extended information: ethnic origin
There is no conclusion about the national origin of the Japanese. There are some records in China's ancient books, especially Shan Hai Jing. Shan Hai Jing is one of the most important geographical documents in human history. It records the distribution of mountains, rivers, landforms, products and nationalities in China and its surrounding areas, as well as the corresponding historical stories, covering the Zhou Dynasty, Shang Dynasty, Xia Dynasty and Pre-Xia Period (10,000 years ago). Among them, the Zhou Dynasty document "Beijing in the Sea" records: "Gaiguo is in the south of Juyan and north of Japan. Japanese swallows. " Other chapters in The Classic of Mountains and Seas tell the story of China people migrating to islands in the East China Sea many times.
References:
Baidu Encyclopedia-Japanese