It is said that Ikeda Kichinojyo, the second son of the priest of Ōmori Daimyōjin, enshrined a portion of the deity of Ōmori Daimyōjin and built a new shrine on Nishiyama. This Nishiyama Shrine was known as Ōmori Daimyōjin and served as the guardian deity for Shimoisaigō six villages in the surrounding area.
In the first year of the Meiji era (1868), the shrine was renamed Nishiyama Shrine, and in the 4th year of Meiji (1871), it was designated as a village shrine.
In May of the 2nd year of the Shōwa era (1927), four other shrines (Higashiidekami Shrine, Mizuguchi Shrine, Ōishi Shrine, and Ueda Shrine) were merged into it, and in October of the same year, it was renamed Toyosaka Shrine. It is a charming shrine with a sacred grove situated in the fields on the southern side of the village, offering a clear and expansive view."