From the method of considering the start of the regency as the dividing line between 'high antiquity' and the time afterwards, it is thought that he borrowed from the "Jinno Shotoki" (A Chronicle of Gods and Sovereigns).
摂関政治の開始を境界線とし、「上古」とそれ以後の時代に区分する方法は『神皇正統記』を援用したと考えられる。