The territory known as the Hata Kingdom (in the coastal regions of the Seto Inland Sea) whose customs and manners were similar to those of China is introduced in "Zuisho" (a history of Sui), and so there is a further theory that this place had something to do with the Hata clan.
『隋書』「」に「」と風俗が中国と同じである秦王国なる土地（瀬戸内海沿岸付近？）が紹介されているが、これを秦氏と結び付ける考えもある。