Okihagi-no-Mikoto and the Shrine’s Mythological Heritage
The principal deity enshrined at Shinkai Sansha Shrine is Okihagi-no-Mikoto, who is traditionally regarded as a grandson of Okuninushi-no-Okami, one of the major deities of Japanese mythology.
According to the shrine’s tradition, his father was Takeminakata-no-Mikoto, the principal deity associated with the famous shrines of Suwa in Nagano, while his mother was Nukisaki-no-Megami, also identified with Arafune Daimyojin and associated with the former Province of Kozuke, present-day Gunma.
This lineage connects the religious traditions of Izumo, Suwa, and the former Kozuke region. Okihagi-no-Mikoto is regarded as a deity associated with the development and cultivation of the Saku area, and generations of local people have looked to him for protection and prosperity.
The Forty-Eight Mounds and Ancient Beliefs
Numerous ancient burial mounds known collectively as the Forty-Eight Mounds are found around the shrine grounds. They are considered possible traces of ancient religious practices and suggest that the surrounding landscape was already regarded as a sacred place long before the shrine took its present form.
For visitors interested in Japan’s ancient history, these mounds provide an intriguing connection between the shrine’s religious traditions and the prehistoric communities that once lived in the Saku region.
From the Medieval Period to the Early Modern Era
Shinkai Sansha Shrine appears in the medieval religious text Suwa Daimyojin Ekotoba, compiled during the Nanboku-cho period. In the text, it is referred to as Niisaku-no-Kami, or the deity of Niisaku, demonstrating the shrine’s recognized religious importance at the time.
The shrine was also known by names such as Saku Shrine and Hiraki Shrine, reflecting its role as a deity and spiritual center associated with the origins and development of the Saku region.
Takeda Shingen and Warrior Devotion
During the Warring States period, the shrine received the devotion of powerful samurai leaders. Takeda Shingen is said to have visited the shrine to pray for victory in battle.
According to historical tradition, Shingen presented a Japanese sword as an offering and arranged for repairs to the shrine buildings. A written prayer attributed to Shingen has also survived, providing a tangible connection to the religious practices of one of Japan’s best-known warlords.
The Edo-Period Debate over Shrine Status
During the Edo period, scholars and local religious figures became concerned that the Saku region did not contain a shrine clearly identified as an Engishiki shrine, referring to shrines listed in the ancient Engishiki legal and ritual records.
A debate emerged over whether Shinkai Sansha Shrine should be recognized as the ancient shrine referred to in those records. Although the issue was never simply a matter of architecture, the debate drew renewed attention to the shrine’s antiquity and status as a major center of local worship.
The Three-Story Pagoda That Survived Religious Reform
One of the shrine’s most remarkable features is its three-story pagoda, built in the late Muromachi period. It originally formed part of a Buddhist temple complex associated with the shrine.
After the Meiji Restoration, the government’s policy of separating Shinto and Buddhism placed many mixed religious sites throughout Japan under pressure. The pagoda at Shinkai Sansha Shrine was also at risk of being demolished.
Local efforts reportedly helped save the structure after it was presented as a treasure storehouse rather than a Buddhist pagoda. As a result, this beautiful medieval structure remains standing within the shrine grounds today.
The Former Grand Procession of the Shrine
In earlier times, the shrine held a major religious ceremony known as Miyuki. During this procession, priests traveled on horseback through a wide area extending across Saku and into the neighboring Chiisagata region.
The route taken during the procession became known as the Shinkaido, or “New Road,” and became deeply familiar to communities throughout the region. The ceremony illustrates how the shrine’s influence once extended far beyond its immediate grounds.
Important Cultural Properties
The shrine contains several valuable historic structures and artifacts.
Three-Story Pagoda: Built in 1515 during the late Muromachi period, this three-bay, three-story pagoda features a traditional wooden-shingle roof known as kokerabuki. It was designated an Important Cultural Property in 1907.
East Main Shrine: Built during the late Muromachi period, between 1467 and 1572, this sanctuary enshrines Okihagi-no-Mikoto. It was designated an Important Cultural Property in 1937.
Mitamashiro Stone: This historic stone monument bears a date inscription from 1368, during the Muromachi period, and was designated a Saku City Cultural Property in 1980.
Medieval Documents of Shinkai Sansha Shrine: A collection of three medieval documents, including a prayer attributed to the Warring States period, was designated a Saku City Cultural Property in 1983.
Central and West Main Shrines: Although their exact dates of construction are uncertain, both buildings were designated cultural properties of Saku City in 2002.
Sub-Shrines and a Sacred Natural Setting
The shrine grounds contain several subsidiary shrines, including Kinutasa Shrine and Fukuda Inari Shrine. A combined structure also enshrines twelve eastern subsidiary shrines and twelve western subsidiary shrines.
These numerous sacred sites reflect the breadth of religious traditions that have accumulated here over the centuries.
A huge zelkova tree once stood beside the torii gate. It was traditionally said to have been around 1,000 years old and watched over worshippers as they entered the sacred grounds.
The Sacred Cedar Tree
About 20 meters from the East Main Shrine stands a magnificent sacred cedar tree. In 1940, it was recorded as approximately 30 meters tall, with a trunk measuring about 12 meters in diameter at its base.
Part of the tree was damaged by a fire during the Meiji period. Local parishioners worked together to extinguish the flames and protect the ancient tree. Later, under the guidance of renowned forestry scientist Honda Seiroku, reinforcement work was carried out to support the tree, which had begun to lean.
The Mysterious Legend of Yoshi Pond
Behind the shrine lies a mysterious pond called Yoshi Pond. According to local tradition, a Buddhist monk discovered the pond after receiving guidance from a snake.
The story says that when the monk used water from the pond to make ink and wrote Buddhist Sanskrit characters on paper, the ink penetrated through as many as 36 sheets of paper. This remarkable event is said to have led to the establishment of the shrine’s Goshinpu Festival.
Another local legend tells of a mysterious nighttime ritual. It was said that anyone who saw a priest wearing a white hood while collecting water from the pond after dark would suffer misfortune. Because of this belief, local residents were once said to go to bed early to avoid witnessing the mysterious figure.
A Historic Shrine at the Heart of Saku
Shinkai Sansha Shrine brings together mythology, ancient burial mounds, medieval architecture, samurai history, and living religious traditions. Its connections to the legendary origins of Saku and the deities of Izumo and Suwa give the shrine an especially distinctive place in the cultural history of Nagano.
The surviving three-story pagoda and medieval shrine buildings provide a rare opportunity to encounter historic Japanese architecture in its original religious setting, while the surrounding trees and sacred landscape create a peaceful atmosphere for exploration.
For travelers visiting Saku, Shinkai Sansha Shrine is a fascinating place to discover the layers of history that have shaped the region. Walking through its grounds, visitors can encounter traces of ancient beliefs, medieval warrior devotion, traditional Shinto architecture, and legends that have been passed down through generations.