Guardian of Dogo, Isaniwa Shrine: One of Only Three Hachiman-zukuri Shrines Nationwide and a Sanctuary of Sangaku

Isaniwa Shrine sits enshrined at the top of the stone steps from the Dogo Onsen Main Building. Based on primary sources, this article introduces the shrine that has watched over Dogo for a thousand years, including its history tied to Yuzuki Castle, its main sanctuary built in the Hachiman-zukuri style—one of only three examples in Japan—and the sangaku (mathematical tablets) dedicated there.

Up the Stone Steps Overlooking the Hot Spring Town

Located on a small hill reached by climbing a long flight of stone steps eastward from Dogo Onsen Honkan is Isaniwa Shrine. Also known by the alternative names "Yuzuki Hachimangu" and "Dogo Hachiman," it enshrines Emperor Ojin, Emperor Chuai, Empress Jingu, and the Three Munakata Goddesses. It is an ancient Shikinaisha shrine whose name appears in the Engi-shiki, and has long been connected with the legend of Empress Jingu and Emperor Chuai visiting the hot springs. The official website also introduces it as a shrine located in Dogo with alternative names of Yuzuki Hachiman and Dogo Hachiman, and as a place associated with prayers for fulfillment of wishes, safe childbirth, good matches, family safety, and business prosperity.

A Shrine That Moved Along with Yuzuki Castle

The shrine was originally located where Dogo Park (the site of Yuzuki Castle) is today. It is said that during the Kenmu era, when Kono Michimori, who ruled this land, constructed Yuzuki Castle, the shrine was relocated to its current site. The history of the shrine in Dogo overlaps with the history of those who ruled the hot spring town. The very act of climbing the stone steps becomes a path to trace the local change of the shrine moving from Dogo Park up onto the hill. Visiting Dogo Park and Isaniwa Shrine consecutively also allows one to turn attention to the positional relationship between the Yuzuki Castle ruins and the shrine.

"Hachiman-zukuri" with Only Three Examples Nationwide

The existing shrine pavilion was constructed in 1667 by Matsudaira Sadanaga, lord of the Matsuyama Domain. This shrine pavilion is in the style called Hachiman-zukuri, said to model Iwashimizu Hachimangu in Kyoto, and is a rare structure with only three examples nationwide alongside Usa Jingu in Oita and Iwashimizu Hachimangu in Kyoto. It is designated as a National Important Cultural Property, and the vermilion-lacquered shrine pavilion stands out above the stone steps. The official website explains that the entire building is a nationally designated Important Cultural Property and is one of only three examples of fully formed Hachiman-zukuri in Japan. When viewing the shrine pavilion, attention can be paid not only to the history of the shrine, but also to the form of the overall shrine building and its vermilion exterior.

Sangaku and Long Swords: Inherited Treasures

Within the grounds, 22 sangaku (wooden tablets with Japanese mathematical problems and solutions inscribed on them, offered to the deities) dedicated from the late Edo period through the Meiji period have been preserved and are designated as Tangible Folk Cultural Properties of Ehime Prefecture. They recall the enthusiasm for learning among the people of that time who dedicated mathematical questions before the deities. In addition, a tachi long sword with the inscription "Kuniyuki" is preserved as an Important Cultural Property. The official website announces that a treasure catalog featuring non-public treasures, starting with the nationally designated Important Cultural Property tachi sword Kuniyuki, is distributed at the shrine office. Through the sangaku and treasures, as well as the building, one can come into contact with the culture of prayer, learning, and dedication.

Annual Events and Contemporary Worship

On the official website, there is information on Nagoshi-sai, Autumn Festival, Annual Grand Festival, Shichi-Go-San, Hatsumiyamairi (first shrine visit for a newborn), and weddings. The Nagoshi-sai is an event based on the myth where Susanoo-no-Mikoto told Somin Shorai that wearing a chinowa (grass ring) around the waist would ward off plagues. The prayer guide also lists safe childbirth, Hatsumiyamairi, Shichi-Go-San, weddings, and Jichinsai (groundbreaking ceremonies). During worship, looking at the shrine pavilion beyond the stone steps, the handed-down sangaku, and the information on events and prayers as separate pieces of information makes it easier to organize the roles the shrine has played. The annual festival is held on October 6.

The official website also provides entrances to the main shrine buildings and subordinate shrines, sacred treasures, sangaku, photo albums, and access guides, allowing visitors to confirm history and shrine pavilion information before and after visiting. Shifting interest to handed-down items such as sangaku and long swords, and guidance on Nagoshi-sai and Autumn Festival after examining the form of the shrine pavilion allows one to trace the architecture, treasures, and events separately. Beyond climbing the stone steps, one can see overlapping views of its present role as a place of prayer and its status as a cultural asset conveying the history of Dogo.

* The opening status of the shrine buildings and event schedules are subject to change. Please check on-site and official information when visiting.