Hakka and Japanese Culture
Hakka culture might be a key component of Japanese culture.
It is hard not to notice that spoken Hakka dialect/language and Japanese language are closer than Mandarin and Japanese. Certain Japanese also resemble Shandong Chinese, distinct from the Ainu features of Hokkaido. Some Japanese friends point out that Hakkas look like Japanese. In fact the strong adherance to tradition and stubbornness are very characteristic of both Hakka and Japanese. The following is an account that could provide some support to the link between Hakka and Japanese culture.
Qin dynasty, Xu Fu, Yamoto, and Yayoi culture
The earliest record of Chinese travelling to Japan was in Qin dynasty when Qin Shihuangdi sent Xu Fu with a company of 3000 boys and girls to obtain longevity medicine. They started out from Shandong and reached what they called Peng Lai (Ying Zhou) which is Kyushu today. In Kyushu, there are significant traces of Xu Fu and his company including Xu Fu's tomb. Xu Fu's landing place should be around Fukuoka (The Hill of Fu), which was named in memory of him.
To be entrusted by Qin Shihuangdi with such an enormous task at that time, Xu Fu at 36 years of age was obviously a very capable person who was also higher up in the official rank. One theory is that he actually used this proposal to leave Qin. He brought a whole fleet of ships fully loaded with all kinds of supplies. It is also clear that Xu Fu had travelled back to China more than once to gather supplies. So, likely he brought more people over for the long trip. The crew he brought over stayed in Japan and became the Yamato clan. That is why some Japanese look like Shandong people, which should be Han/Hakka in genetic trait.
The history of Japan is very vague as to how the empire started. Only legends exist. Japanese culture has two major components: The Jomon culture and the Yayoi culture. The native Jomon culture was based on hunting and fishing, dating back to 10,000 years ago.
The Yayoi culture, which suddenly emerged around 250 BC - 250 AD as a very advanced culture, bears all the marks of Qin/Han culture including paddy rice cultivation, bronze mirror, coins, bronze weapons, bells, etc. The three major symbols of the Japanese Kingdom : bronze mirror, sword, and the royal seal stone are exactly the same as the Qin symbols. With no archaeological precedent of a gradual evolution, Yayoi culture has to be introduced from outside, and the most probable source was China. The Yayoi culture spread northeastward towards the Kanto plain and eventually became the mainstream of the Japanese culture.
Japan's celebration of the "birthyear" of Shen Wu Tian Huang (Ten-no) was held every 50 years (last held 1930 and 1980) as a very sacred ceremony simultaneously in a memorial celebration of Xu Fu. The beginning of Shen Wu Tian Huang was in the same time period of Xu Fu's landing in 219 BC. So these two are too coincidental not to be related. Shen Wu Tian Huang is supposed to be the Father of the Japanese kingdom. The celebration actually could be for the birthyear of the Empire rather than a person.
Did Xu Fu start out from Shandong or Guangdong?
There is also a hypothesis that Xu Fu started out from Guangdong because the spoken Japanese sounds like Guangdong dialect more than Mandarin. However, Qin Shihuangdi's active area was in the north. It would be hard to trust someone so far from the south. The climbing of Taishan (Shandong) by Qin Shihuangdi was well documented by Li Si's stone engravings on Taishan. So, Shandong is a place frequented by QSHD. It is natural that he might want to watch the ships set sail to fetch the longevity medicine too. As pointed out by a netter friend, Shandong dialect actually has some similarities to Hakka (see language page). If Hakka was indeed the official language commonly used in Qin-Tang dynasties, then that was the language Xu Fu and his crew spoke. So, it would be natural for the Japanese spoken language to bear some resemblance of Hakka.
Buddhism, Wei - Tang period
Buddhism was spread to Japan during Wei-Jin and Tang period. There were more and more interactions between the two countries. In Wei Zhi (history of Wei) the word "Wo" (Japanese "Wa", Mandarin "He") first appeared to represent the Japanese kingdom.
Hakka language was highly likely the official language in Tang dynasty (see language section about Tang poems). In Japan, much of the government bureaucratic system, including the names of bureaus still use the system developed from Qin-Han to Tang period.
Examples of ancient Han/Hakka culture and Japanese culture
Japanese culture retains many of the ancient Chinese custom including deep bowing, seating on tatami with low table (only after Song did high chairs become popular in China), the women's dress and headdress, the way pipa ( a pluck string musical instrument, Japanese call it biwa) is held at an angle rather than upright. These can be easily verified in the murals of Dun Huang, which were done from Wei-Jin to Tang. In terms of calligraphy, the early Japanese masters favored Wang Xi-Zhi (Jin) while the contemporaries follow Yan Zhen-qing (Tang).