Recently, Hiromichi MAYUZUMI's study pointed out the possibility that the surviving fragment of "Joguki" is a remaining document from the Reign of Empress Suiko, and, even though its credibility and the truth of genealogy remain an open question as mentioned above, the tradition of genealogy appears to have been established around the same time as when Gentekiki (the ur-text of Teiki [records of Emperor's family tree]) was compiled (possibly in the reign of Emperor Kinmei).
『上宮記』逸文は近年、黛弘道の研究によって推古朝の遺文である可能性も指摘され、その内容の信憑性や実際の血統については前述のとおり議論が分かれているものの原帝紀の編纂（欽明天皇朝か）と同じ頃に系譜伝承が成立したものと思われる。