Kamo no Yasunori (賀茂保憲)

KAMO no Yasunori (917-March 14, 977) was the Onmyoji (diviner) and Inyoka (the Yin and Yang school of philosophy) of the mid-Heian Period. He was the eldest son of KAMO no Tadayuki. He was said to be the master of ABE no Seimei or his senior apprentice. He had YOSHISHIGE no Yasutane, who had the rank of Naiki Shonin (Imperial Secretary who was allowed to enter the imperial court), as his younger brother, KAMO no Mitsuyoshi and KAMO no Mitsukuni, who was assigned to be the Gon no tenmon hakase (Assistant Master of Astronomy) as his sons, and KAMO no Yasunori no Musume (daughter of KAMO no Yasunori), who was the waka (Japanese poem) poet, as his daughter.

He was the master of Onmyodo (way of Yin and Yang; occult divination system based on the Taoist theory of the five elements) similar to his father, KAMO no Tadayuki, and although there was no confirmation, he successively held the post of the Onmyo no kami (Director of Onmyoryo, or Bureau of Divination). He studied Rekido (study of almanacs from the use of astronomy) and wrote "Rekirin" (the forest of Almanac). According to the "Konjaku monogatari shu" (The Tale of Times Now Past), he accompanied the exorcism that his father was asked to do, and told his father, Tadayuki, that he saw numerous oni (Japanese ogre) gather around the offering at the time of the exorcism. Tadayuki was surprised that his own child had the talent of Kenki (the ability to see spirits) without training, and instructed him Onmyodo from that time hence. He consecutively held the posts of Onmyoto, tenmon hakase (master of astronomy), reki hakase (master of reki (calendar)), Kazue no kami (the head of the budget bureau), Kokuso-in betto (Chief of the Grain warehouse) and declared a Senji (Imperial decree) for creating a calendar, and was given the Jo rank (imperial court rank) of Jushii (Junior Fourth Rank). Since he felt apologetic for having an official court rank higher than his father, there was an occasion where he asked for the promotion of his father, Tadayuki. The 'Rekirin' that he left is used as a valuable source even now in reading what is called the old calendar and it can be said that there have been no later development of rekiho (method of making calendars) without him.

He passed down the Rekido of Onmyodo to his son, KAMO no Mitsuyoshi, and passed down Tenmondo (ancient horoscopy) to ABE no Seimei, and was famous for dividing the head of the Onmyodo family into two. According to the "Zoku kojidan" (Tales of Antiquity Continued), ABE no Seimei and KAMO no Mitsuyoshi debated on which of them their master KAMO no Yasunori was not looking forward to.