After the middle Heian period, during which ABE no Seimei, who succeeded to the art of tenmondo from KAMO no Yasunori, was active, the study became the hereditary learning of the Abe clan (later the Tsuchimikado family) and the clan showed a tendency to exclude people from other families.
更に平安時代中期に賀茂保憲から天文道を継承した安倍晴明以後、天文道は阿倍氏（後の土御門家）の家学となり、他氏の者が関わることを避ける傾向が現れた。