The tale of Ōyama Hōkibō stands upon the history of the sacred mountain Sagami Ōyama and upon the distinctive lore-structure of a tengu's "seat transfer."

Mt. Ōyama of Sagami, also called Afuri-yama, had its divinity established in antiquity. The Engishiki Jinmyōchō (927)^[2] ranks the Afuri Shrine on its summit among the official shrines of Sagami Province, with Ōyamatsumi-no-kami as the enshrined deity. On the Buddhist side, the Ōyama-dera engi emaki^[4] opens with the wife and husband of the Sagami governor praying to Kannon for the gift of a child, and depicts how Rōben—carried off by an eagle and raised in Nara—opened Ōyama-dera in the Tenpyō-shōhō era and enshrined the honzon Fudō Myōō (this Sagami version of the engi emaki is, moreover, a different work from the engi of the same-named Daisen-ji of Hōki Province). From the medieval period onward, Shugendō flourished with this Ōyama-dera as its base.

In early-modern times the "Ōyama pilgrimage" (Ōyama mairi) became a great popular event. The official gazetteer the Shinpen Sagami no Kuni Fudoki-kō (1841)^[5] sets the festival from the twenty-seventh of the sixth month to the seventeenth of the seventh, and records that pilgrims from many provinces were exceedingly numerous. Pilgrims took the water-austerity (mizugori) at two waterfalls before making the ascent; Ōyama confraternities (Ōyama-kō) were organized throughout the Kantō, and the guiding sendatsu-shi (oshi) marshaled the pilgrimage.

What characterizes Hōkibō as a tengu is this "seat transfer" tradition. When Sagamibō, originally lord of Sagami Ōyama, removed to Shiramine to guard the spirit of the Retired Emperor Sutoku—who lost the Hōgen Rebellion and died in Sanuki—Hōkibō came from Hōki's Daisen to Sagami as his successor. This paired structure, as far as can be verified, is something Chigiri Kōsai^[3] arranged in the course of systematizing the tengu tales of the provinces, and an explicit textual source is hard to find in the classical literature. Telling of Ōyama Hōkibō therefore leads naturally to telling of Shiramine Sagamibō and Sutoku's vengeful spirit, while the seat-transfer itself should be read as a later arrangement. After the Meiji separation of Shintō and Buddhism (shinbutsu-bunri), an interpretation arose at Ōyama Afuri Shrine assigning Ōikazuchi-no-kami as the great tengu and Takaokami-no-kami as the lesser tengu; but this is a modern reinterpretation accompanying Shintoization, of a different stratum from the image of Hōkibō handed down since the medieval age.