The Origins and Legends of Akagi Shrine
Ancient Roots of Mountain Worship
The exact date when Akagi Shrine was founded is unknown, but its origins are believed to extend back to ancient times. Mount Akagi was already known to people in antiquity, and it is mentioned in the Man’yoshu, Japan’s oldest major anthology of poetry, where the mountain is referred to as “Kuroho no Nera”.
The religious traditions of Mount Akagi are thought to have developed from several forms of nature worship. These included reverence for Lake Konuma as a source of water, worship of deities associated with thunder and rainfall, and belief in the sacred nature of the mountain itself.
The Formation of Akagi Mountain Worship
Mount Akagi is a large volcanic mountain range consisting of several peaks, including its highest summit, Mount Kurohiyama, as well as Mount Komagatake and Mount Jizodake.
At the center of the mountain range are Lake Onuma, a caldera lake, and Lake Konuma, a volcanic crater lake. These lakes and surrounding mountains were regarded as sacred places from ancient times.
For early communities living around the mountain, water was essential to agriculture and everyday life. Reverence for the water sources gradually became intertwined with worship of mountain and weather deities. In this way, the religious tradition of Akagi developed around the idea that the mountain was a sacred place where divine powers resided.
The Connection with the Kamitsukeno Clan
One theory concerning the origins of Akagi worship connects it with the ancient Kamitsukeno clan, a powerful local family in the former province of Kozuke, corresponding roughly to present-day Gunma Prefecture.
One of the deities worshipped at Akagi Shrine is Toyoki-iri-hiko-no-Mikoto, who is traditionally regarded as an ancestral deity of the Kamitsukeno clan. This connection suggests that the religious tradition of Mount Akagi may have been closely associated with the political and cultural development of the region in ancient times.
Akagi Worship in the Heian Period
During the Heian period (794–1185), Akagi Shrine came to be recognized as an important shrine by the imperial government. Historical records such as the Shoku Nihon Koki and Nihon Sandai Jitsuroku record the granting of increasingly high court ranks to the deity of Akagi.
The deity was granted the rank of Junior Fifth Rank, Lower Grade in 839, followed by higher ranks in 867 and 880. By around the 11th century, the deity was recorded as having the exceptionally high rank of Senior First Rank, indicating the importance of Akagi worship in medieval Japan.
Akagi Shrine in the Engishiki
Akagi Shrine is also listed in the Engishiki, a major compilation of laws, regulations, and shrine records completed in the early 10th century. It appears in the shrine register as Akagi Shrine of Seta District, Kozuke Province.
The shrine was classified as a Myojin Taisha, one of the highest categories of important shrines recognized by the ancient Japanese state.
However, the precise location of the shrine recorded in the Engishiki remains uncertain. Three historic shrines in and around present-day Maebashi are traditionally regarded as possible candidates: Odo Akagi Shrine, Miyosawa Akagi Shrine, and Ninomiya Akagi Shrine.
Three Important Akagi Shrines
The three principal Akagi Shrines in the Maebashi area are:
Odo Akagi Shrine — Akagiyama, Fujimi, Maebashi
Miyosawa Akagi Shrine — Miyosawa, Maebashi
Ninomiya Akagi Shrine — Ninomiya, Maebashi
Each shrine developed a different role within the broader tradition of Akagi worship. They have traditionally been associated with different positions in relation to the sacred mountain, including the mountain shrine, central shrine, and foothill shrine.
Odo Akagi Shrine — The Mountain Shrine
Odo Akagi Shrine stands on Kotori-ga-shima Island in Lake Onuma at the summit area of Mount Akagi. Surrounded by the lake and mountains, its setting is particularly atmospheric and is one of the most scenic places associated with Akagi worship.
Because of its location deep within the mountain environment, the shrine was traditionally regarded as a mountain shrine, closely connected with worship of the mountain itself.
The present shrine buildings were reconstructed in 1970. Today, the shrine is both an important place of worship and a popular destination for visitors exploring the natural scenery of Mount Akagi.
Miyosawa Akagi Shrine — The Central Shrine
Miyosawa Akagi Shrine is located at the southern foot of Mount Akagi in Miyosawa. It developed as an important shrine along the pilgrimage routes leading toward the mountain.
It served as a significant stopping point for worshippers and mountain ascetics traveling toward the sacred areas higher on Mount Akagi. In the past, the shrine complex included separate East and West Shrines, each associated with different deities.
During the religious reforms of the Meiji period, the two shrines were consolidated. Today, Miyosawa Akagi Shrine continues the tradition of worshipping the deities associated with Mount Akagi.
Ninomiya Akagi Shrine — The Foothill Shrine
Ninomiya Akagi Shrine is located in Ninomiya, Maebashi, at the foot of the mountain. It is traditionally regarded as a foothill shrine that served as a center of worship for communities living in the surrounding lowlands.
For people who could not make the difficult journey into the mountains, a foothill shrine provided a more accessible place to pray to the deities of Mount Akagi.
The shrine declined during the upheavals of the Warring States period but was restored during the Edo period. It subsequently continued to serve as an important local guardian shrine.
Akagi Shrine and the Fusion of Shinto and Buddhism
During Japan’s medieval period, the religious traditions of Mount Akagi developed under the influence of Shinto-Buddhist syncretism. This was common throughout Japan, particularly at sacred mountains where Buddhist and indigenous religious traditions became closely intertwined.
Mountain worship at Akagi came to incorporate Buddhist concepts, with Buddhist figures being associated with the sacred lakes and peaks of the mountain.
Mountain Asceticism and Shugendo
From around the Kamakura period onward, practitioners of Shugendo, a Japanese religious tradition centered on ascetic practices in the mountains, are believed to have entered Mount Akagi.
For these practitioners, mountains were places of spiritual training. Their activities helped spread religious traditions that regarded Buddhist and Shinto deities as interconnected aspects of a sacred world.
During this period, the religious landscape of Mount Akagi became associated with the “Three Akagi Deities”, centered on three sacred locations: Lake Onuma, Lake Konuma, and Mount Jizodake.
The Three Sacred Sites of Akagi
Lake Onuma was associated with Senju Kannon, the Thousand-Armed Kannon.
Lake Konuma was associated with Kokuzo Bosatsu, Akasagarbha Bodhisattva.
Mount Jizodake was associated with Jizo Bosatsu, Ksitigarbha Bodhisattva.
These associations demonstrate how the natural landscape of Mount Akagi was incorporated into a sophisticated religious system combining mountain worship, Shinto traditions, and Buddhism.
Akagi Shrine During the Edo Period
During the Edo period (1603–1868), Akagi Shrine received strong support from the lords of the Maebashi domain.
In 1601, the domain lord Sakai Shigetada supported the renovation of the shrine buildings. Subsequent lords continued to provide assistance for construction and religious ceremonies.
Odo Akagi Shrine was particularly revered as a shrine protecting Maebashi Castle’s northeastern direction, traditionally regarded in Japanese geomancy as an important and potentially vulnerable direction.
The domain lord is also said to have attended major shrine festivals, demonstrating the special status that Akagi Shrine held within the domain.
Disputes over the Main Akagi Shrine
During the Edo period, a dispute arose between Odo Akagi Shrine and Miyosawa Akagi Shrine concerning the name and status of the principal Akagi Shrine.
The disagreement was eventually resolved through discussions between the parties, allowing both shrines to preserve their respective traditions. This history illustrates the complex development of Akagi worship, in which several historic shrines maintained important roles rather than being reduced to a single institution.
Changes After the Meiji Restoration
The religious landscape of Japan changed dramatically during the Meiji period (1868–1912). The government introduced policies separating Shinto from Buddhism, and many temples, Buddhist statues, and other Buddhist elements were removed from shrine complexes throughout Japan.
Akagi Shrine was also reorganized under the new system. Miyosawa Akagi Shrine was designated a prefectural shrine, while Odo Akagi Shrine and Ninomiya Akagi Shrine were classified as village-level shrines under the modern shrine ranking system.
During the Showa period, there was also an effort to have Akagi Shrine elevated to the status of an imperial government shrine, although this did not come to fruition because of the circumstances surrounding the Second World War.
Akagi Worship Spreads Throughout the Kanto Region
The worship of Akagi is not limited to Gunma Prefecture. Shrines dedicated to Akagi are found throughout the Kanto region, with more than 100 said to exist within Gunma alone.
Across Japan, the number of Akagi Shrines is traditionally said to exceed 300. Some were established by communities that already worshipped Mount Akagi, while others were created after the enshrinement of divided or invited deities from existing Akagi shrines.
In this way, the religious tradition of Mount Akagi spread far beyond the mountain itself and became incorporated into the everyday spiritual life of communities throughout the region.
Mount Akagi — A Sacred Mountain of Northern Kanto
Mount Akagi rises along the northwestern edge of the Kanto Plain and is actually a volcanic mountain complex rather than a single peak. Its highest summit is Mount Kurohiyama, at 1,828 meters, surrounded by peaks including Mount Komagatake, Mount Jizodake, and Mount Suzutake.
Caldera Lakes and a Sacred Volcanic Landscape
The upper part of Mount Akagi features a volcanic caldera containing Lake Onuma and Lake Konuma. The area also includes the wetland of Kakumanbuchi, creating a distinctive natural landscape that changes dramatically with the seasons.
The combination of mountain peaks, forests, lakes, and wetlands helped inspire the ancient belief that divine beings inhabited the landscape. The mountain came to be revered through various forms of mountain, water, and weather worship.
For this reason, Mount Akagi developed into one of the important sacred mountains of the Kanto region.
Akagi Shrine Today
Today, Akagi Shrine remains an important religious and cultural symbol of Gunma while also serving as part of the sightseeing experience on Mount Akagi.
In particular, Odo Akagi Shrine beside Lake Onuma is a popular destination because of its striking setting surrounded by water and mountains. The scenery changes throughout the year, with fresh greenery in spring, cool highland air in summer, colorful autumn foliage, and snowy landscapes in winter.
Visitors also combine a visit to the shrine with outdoor activities on Mount Akagi, including hiking, mountain walking, and smelt fishing during the appropriate season.
A Place Where Nature, History, and Faith Meet
Akagi Shrine represents a long tradition of worship deeply connected with the natural landscape of Mount Akagi. Long before modern tourism, the mountain’s lakes, forests, peaks, and water sources were regarded as sacred and became the focus of prayer and ritual.
Today, visitors can experience this history while enjoying the spectacular natural scenery of the mountain. A visit to Akagi Shrine is therefore not only an opportunity to see a historic Japanese shrine, but also a chance to understand the tradition of mountain worship and the close relationship between nature and spirituality in Japanese culture.
When exploring Mount Akagi, take time to appreciate both the scenery and the centuries of religious history that have made this mountain one of Gunma’s most important sacred landscapes.