History

The shrine was founded in 1627 when a senior monk of the Eitai-ji temple, Chōsei Hōin (長盛法印), received oracular guidance in several dreams to build a shrine at Eitaijima, the then name for the area where the shrine currently is. A variation on this says that Chōsei was a descendant of Sugawara Michizane and had in his possession an image of Hachiman made by the master. Chōsei was living in Kyōto when he had his dream and he was instructed to go to Edo and find an appropriate place to house the image. The year was 1624. He went to Edo and after wandering the streets for a long time found a hokora (small shrine) in what was then the largely unpopulated Eitaijima area. After three years of work reclaiming the wetlands with his own hands he was finally able to open the shrine in 1627.

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Another account tells us that this Tomioka Hachiman-Gū is a branch of the one in Kanazawa-ku in Yokohama. In the early Edo Period land reclamation was underway in the area and as a result of this work running into difficulties the shrine was spun off from the one in Kanazawa-ku through the bunrei process and was apparently temporarily known as Namiyoke (Seawall) Hachiman. The amount of land reclaimed and then owned by the shrine was slightly over 200,000 m2. The Tokugawa Shōgunate supported the shrine; along with the Meiji Restoration it was given Junchokusai status and in 1975 it became one of the Ten Tōkyō Shrines.