The most popular version is of course the story of Xu Fudong crossing the river. It is said that Qin Shihuang sent alchemist Xu Fu to lead 500 boys and girls to Japan to look for elixir of life, and later settled here, and even Xu Fu became the first emperor of Japan. Xu Fu brought writing, farming and medicine to Japan. In this way, Xu Fu was honored as a "god of agriculture" and a "god of medicine" by the Japanese, and there are still many sites of Xu Fu in Japan until now. In order to prove that Xu Fu is the ancestor of the Japanese, the Japanese also took great pains and even had archaeological evidence. Many bronzes and carbonized rice have been unearthed in Japan, which shows that people from China traveled eastward during the Qin and Han Dynasties. There is still a tomb of Xu Fu in Japan. Every year, there are activities such as "Royal Boat Festival" and "Lantern Festival" to worship Xu Fu.
Another version is that the ancestors of the Japanese immigrated from the Korean peninsula, mainly considering the geographical proximity of the Korean peninsula and Japan. This view is probably the main argument that Koreans speak Japanese originated from Koreans.
There is also a folk joke that the Japanese are descendants of Wu Dalang, and Wu Dalang escaped Pan Jinlian, but became a magical power. Facing Pan Jinlian, who doesn't behave like a woman, Wu Dalang, who sees through the world of mortals, leads hundreds of younger brothers to practice overseas. I happened to discover the new continent four or five hundred years earlier than Columbus, so I slowly lived in seclusion with my descendants, but it also caused the Japanese to be generally short.
Some of the above versions are widely circulated, but there is no conclusive evidence, and some versions are even a bit absurd. According to research, primitive humans lived in Japan tens of thousands of years ago. Although the sparrow is small and complete, there is a view that the Japanese population is made up of ancient immigrants, including Siberia, Korea, China and even Malaysia. It can be said that the Yamato nationality is a mixed nationality.
Where the Japanese ancestors came from may require further textual research and research.