The Yasedoji were considered descendants of Oni (a creature from Japanese folklore) whom Dengyo Daishi Saicho (Buddhist Monk named Saicho with the posthumous title of Dengyo Daishi) employed in Doji mura (village) as a domestic laborer for the Enryaku-ji Temple.
延暦寺の雑役に従事した童子村で伝教大師最澄が使役した鬼の子孫とされる。