The Aso clan started with Kannushi worshiping the kami of Mount Aso area and later became the head of the Agata by presenting their land to the Yamato Ouken and later to the group in power as an organized manor (shōen). They became a powerful group of samurai, and they named themselves a Dai-guji, or great Kannushi and the top of gōzokus or samurai combined. It is said that Aso Shrine was the earliest shrine in Higo Province and included lower shrines such as Kengun Shrine in Kumamoto, Kosa Shrine, and Kouriura Shrine which extended the area of influence.