Isasumi Shrine (伊佐須美神社)

Isasumi Shrine stands on what was once an island in a vanished lake. The shrine’s foundation myth claims the four kami enshrined here descended to this spot when the Aizu Basin was still underwater, and through divine will drained the lake to create habitable land. Today, the shrine occupies a quiet grove in Aizumisato, Fukushima Prefecture, surrounded by rice fields that exist only because of that mythological transformation. The lake is gone, but the island remains — a raised terrace of ancient ground where cedar trees grow taller than anywhere else in the basin.

Isasumi Shrine is considered the ichinomiya (first-ranked shrine) of the former Iwashiro Province, a position it has held since at least the early Heian period. The shrine was founded in the 2nd century BCE according to shrine records, making it one of the oldest continuously operating religious sites in the Tōhoku region. The name “Isasumi” derives from isa (merit, achievement) and sumi (to dwell), meaning “dwelling place of meritorious deeds.” The current shrine buildings were reconstructed in 2008 after a devastating fire destroyed the Edo-period structures, but the reconstruction faithfully followed the original gongen-zukuri style. Archaeological surveys of the grounds have uncovered ritual objects dating to the Yayoi period, confirming the site’s extreme antiquity.

Ōhiko no Mikoto is the primary deity, a legendary general sent by Emperor Sujin in the 1st century BCE to pacify the northern regions. He is enshrined alongside Takehiko no Mikoto (his son), Princess Nunakawa (Takehiko’s wife), and Kenu no Sukune (Takehiko’s younger brother). Together, these four kami are known as the “Land-Opening Deities of Aizu.” Ōhiko and his family are credited not only with military pacification but with introducing rice cultivation, irrigation engineering, and sericulture to the Aizu region. The shrine’s messenger is the white horse, and white horses were historically kept on the grounds as living offerings.

When Ōhiko no Mikoto arrived in Aizu around 100 BCE, the basin was dominated by Lake Inawashiro, with only isolated islands breaking the surface. Standing on the island now occupied by the shrine, Ōhiko performed rituals for seven days and seven nights, after which the earth trembled and a fissure opened at the eastern edge of the lake. Water drained through the new channel, revealing fertile land. The local population, astonished, pledged loyalty to Ōhiko and built a shrine on the island to honour him. This legend is sometimes interpreted as a mythologized account of actual land reclamation projects — Ōhiko may have directed the digging of drainage channels that transformed marshland into rice paddies, engineering work remembered as divine intervention.

The main sanctuary, rebuilt in 2008, follows the traditional gongen-zukuri style with a connecting corridor linking the worship hall and main hall under a single roof. The vermilion-lacquered structures stand against a backdrop of ancient cedars, some exceeding 600 years of age. The shrine grounds contain the Yakushido (Medicine Buddha Hall), reflecting centuries of shinbutsu-shūgō (Shinto-Buddhist syncretism) before the Meiji separation. A sacred pond called Kagami-ike (Mirror Pond) occupies the western edge of the precinct, said to mark the original shoreline of the ancient lake. The shrine’s Homotsuden (treasure hall) houses Important Cultural Properties including 12th-century Buddhist statuary and Muromachi-period sword blades.

• Otaue Matsuri (Rice Planting Festival, June 15) — Ritual planting of sacred rice in the shrine’s paddies, performed by miko in traditional dress with folk songs and dengaku field music, honouring Ōhiko’s gift of agriculture to Aizu.
• Reitaisai (Grand Festival, September 12) — The annual celebration featuring mounted samurai processions and yabusame horseback archery, commemorating Ōhiko’s military heritage.
• Hashigo-nori (Ladder Festival, January 14) — Firefighters perform acrobatic feats atop tall ladders, a tradition unique to Isasumi and dating to the Edo period.

Late May, when the wisteria in the shrine garden reaches peak bloom. The 300-year-old wisteria arbour produces clusters that hang nearly two metres long, filling the air with fragrance. Autumn is equally compelling — the shrine forest turns brilliant gold and crimson in early November, and the crowds remain manageable compared to Kyoto’s famous temples. For those interested in living ritual, the June rice-planting festival offers a rare glimpse of agricultural ceremony performed as it has been for centuries.