Kamo no Yasunori (賀茂 保憲) was an onmyōji, a practitioner of onmyōdō, during the Heian period in Japan.

According to a tale in the Konjaku Monogatarishu, at the age of ten, Yasunori accompanied his father to an exorcism, where he was able to perceive the demons — a sign of talent, for, unlike Tadayuki, Yasunori was capable of doing so without formal training.

Seimei became his successor in astrology and divination, while Yasunori's son succeeded him in the creation of the calendar, a lesser task.

In the play, he is the owner of the Kin'u Gyokuto Shū, a book of divination passed down from a Chinese wizard.

This sets the stage for a conflict between Ashiya Michitaru (as Dōman is called in the play) and Abe no Yasuna over ownership of the book.