Ena Jinja Shrine and Mt Ena (Placenta Belief)

The founding date of Ena Shrine is unknown, but the shrine appears in the Engishiki Jinmyōchō (927 CE) as 'Ena-no-jinja,' indicating state recognition as a shrine at least by the early Heian period (Yamafile, History of Mt Ena). Mt Ena itself is thought originally to have been the sacred object of worship (Wikipedia 'Ena Shrine'). In the Edo-period gazetteer 'Yosho Ryakku' (by Matsudaira Kunzan), the text reads: 'On the north slope of Mt Ena, there is a rock shaped like a bathing trough. Local tradition holds that when Amaterasu Ōmikami was born here, this was the tub in which the birth was bathed, and that the placenta (ena) from this birth was deposited within this mountain — from which the mountain's name (Ena-yama) and the shrine's name (Ena-jinja) both derive' (Ministry of Land, Infrastructure, Transport and Tourism / KISSO Vol. 13). The shrine's precinct was damaged in Tenshō 2 (1574) when Kiso Yoshimasa, acting on orders from Takeda Katsuyori, captured Atera Castle; a ridge-board inscription of 'Seven Shrines jointly reconstructed' survives from Tenshō 4 (1576) (Wikipedia 'Ena Shrine'). The shrine became the general tutelary shrine of Ena District in Meiji 4 (1871), attained prefectural shrine status in Taishō 14 (1925), and in Shōwa 28 (1953) was designated a Gold-Standard Shrine by the Gifu Prefectural Shrine Association.

Ena (placenta/umbilical cord) belief — treating the placenta and umbilical cord as sacred objects — is a form of ancient East Asian birth-cult, and the practice of burying a sovereign's placenta in a sacred location to bind it with the earth's spirit is documented in Japanese imperial traditions (see e.g. Kumamoto University Repository, 'Shrines Enshrining the Placenta'). At Mt Ena, the placenta of Amaterasu Ōmikami is the object of devotion, and the concept of 'the goddess of the sun's placenta' functions to consecrate the entire mountain as sacred. Regarding the relationship with the Kojiki and Nihon Shoki: in the Kojiki, Amaterasu is born when Izanagi washes his left eye in purification rites at Ahaji-no-hara in Hyūga — a male-bodied birth with no mention of a placenta. In the Nihon Shoki, Nihon Shoki, Book One, Fifth Episode, the text records that Izanagi and Izanami 'together gave birth to the sun deity, named Ōhirume-no-muchi (Amaterasu Ōmikami)' — a birth from both deities, but again without any mention of placenta. The 'Yosho Ryakku' (a late Edo-period regional gazetteer) is the primary source for the Ena placenta tradition, and scholars note that it is a regional early-modern tradition that couples local place-name etymology with mythological narrative rather than a direct citation from the Kojiki or Nihon Shoki.

At the annual festival (29 September), the 'Ena Bunraku' puppet theatre — designated a Gifu Prefectural Intangible Folk Cultural Property — is performed (Wikipedia 'Ena Shrine'). The seven summit shrines function as a site of mountain-pilgrimage faith for those who climb Mt Ena. In Meiwa 4 (1767), the Shugendo ascetic Kakumei conducted 17 days of fasting practice on the mountain. The Chiara-rai Shrine ('Blood-washing Shrine'), which stands beside the 'Chiara-rai Pond' where Izanami is said to have washed away the pollution of childbirth, is located in the same Kaore district as the main Ena Shrine, forming a geographically coherent system of placenta belief.

The main shrine (front shrine) can be visited year-round; the annual festival on 29 September is the optimal occasion. For the summit shrines, late May through early November (outside of snow season) is recommended; the Hirokawara Route via Ena-yama Weston Park is the standard approach (8–10 hours round trip).

The front shrine is a simple, unadorned hall set in the stillness of deep mountain woods — the approach and torii gate make the most suitable composition. The seven summit shrines stand in a row in the alpine meadow above 2,000 m, and the high-mountain landscape behind them makes for an impressive composition.

Mt Ena is a full-scale mountain climb listed among the 100 Famous Mountains of Japan; visiting the summit shrines requires a mountain hike of 8–10 hours or more round trip. Proper mountaineering equipment is mandatory (topographic map, food, rain gear, headlamp). Even in summer the summit area is cold and subject to sudden weather changes. File a mountain-entry notification with the Nagano or Gifu Prefectural Police before ascending.