The Nagano Shrine was known as “The Shrine of Koyado” or” Gozu-Tenno Shrine(Susanoo-no-Mikoto God of the Sea and Storm)”. It is said that its origin comes from a court noble who served to the Emperor Go Murakami during the Northern and Southern Dynasty (Nanbokucho) Period, prayed to welcome the Susanoo-no-Mikoto God of the Sea and Storm. From 1868 (year 4 of Keio period) it was named Nagano Shrine. The Main Sanctuary is a Nationally Designated Important Cultural Property.
(quote from “KŌYA MŌDE” published by the Kawachinagano City Board of Education)