Akagi Mountain Great Pond Legend

The Akagi Mountain Great Pond Legend is a mountain-worship account focused on Akagi Daimyojin, the kami said to inhabit the Great Pond (Ōno), a caldera lake at the summit of Akagi Mountain in Maebashi, Gunma Prefecture. According to tradition, a great serpent or dragon deity dwells at the mountain's peak. The narrative's core is the "Akagi-Nikkō Divine Conflict" (*Akagi-Nikkō shinsensō*), a medieval tale recounting a territorial dispute over Lake Chūzenji between Akagi's kami and the centipede-spirit (Ōmukade) that serves as guardian of Mount Nikkō's Otoko peak. With the aid of Kashima's kami, Takemikazuchi, Akagi's deity took up bow and engaged in fierce combat on the lake's surface, eventually reaching peace through accord. At the mountain's base, Akagi Shrine stands on the small island of Kotori-ga-shima within the pond itself, treating the lake as a sacred realm.

The narrative structure comprises three movements: the territorial dispute between Akagi and Nikkō deities; the lakeside battle with divine reinforcement; and the establishment of peace and ritual worship. The confrontation between these two major peaks of north-central Honshū exemplifies Kantō mountain-worship tradition, weaving together motifs of lake, mountain, and serpent form. Within the medieval *Shugendo* context, the legend developed connections to Tendai Buddhist foundational accounts (*engi*), elevating Akagi's kami to prominence as supreme mountain deity.

The primary sites are the Great Pond and Akagi Shrine on Kotori-ga-shima in Maebashi, Gunma Prefecture, along with associated shrines including Miyosawa Akagi Shrine and Ninomiya Akagi Shrine at the mountain's base. These collectively held administrative standing as the principal shrines of Kōzuke Province. The opposing narrative domain centres on Lake Chūzenji and Futarasan Shrine in Nikkō, Tochigi Prefecture; both regions have formed an integrated mountain-worship sphere since the medieval period.

The legend appears in medieval foundational accounts such as *Akagi Shrine Engi* and *Nikkō Mountain Engi*, with the narrative systematised in early modern geographical texts including *Kōzuke Province Records* and *Miscellaneous Jōmō Legends*. It does not appear in the classical Japanese chronicles (*Kojiki*, *Nihon Shoki*), and is situated as an independent narrative tradition established from the late Heian through medieval periods. Shrine records of Akagi Shrine and cultural heritage documentation from Maebashi and Gunma Prefecture provide foundational reference.