In this essay I try to answer to a question which appeared on Quora regarding the relationship between the Chinese and Japanese Emperors. The official (Chinese) documents only report a few accounts of the state of Japan starting from the I Century CE. Sima Qian reports an earlier legend, of the times of Qin Shih Huangdi, the emperor of the terracotta warriors, but again, the hero of the story, XuFu, is just a shaman, half magician and half impostor, unrelated, as far as I know, to any of the earlier Chinese Imperial dynasties. To find a legend which might relate to each other the one Japanese Imperial Dynasties, and all the Chinese Dynasties until the Later Han, one must resort to a tradition first reported by the Northern Wei historical documents.