Until then, the three department of Onmyoryo (Bureau of Onmyodo: a government office that had jurisdiction over calendar preparation, astronomy, divination, etc.) (Onmyodo), Tenmondo (astrology), Rekido (learning of the calendar) and Onmyodo, were divisively undertaken by each specialists; however, KAMO no Tadayuki, who was a Rekika (scholar of Rekido), controlled all the three department beyond these scopes of duties and established the Kamo clan, the family that produced yin yang philosophers.
それまで陰陽寮（陰陽道）の天文道・暦道・陰陽道の三部門はそれぞれ専門家による分業であったが、暦家である賀茂忠行はその職掌を越え、この三つをもすべてを掌握し、陰陽家・賀茂氏を確立した。