History

Unlike Shinmei-Gū Jōge-niza, Sansha Jinja is one of the 448 shrines for which the Nagano-ken Association of Shintō Shrines offers some information. Unfortunately it is very limited, and its "history" section, just 65 characters long, is more descriptive than historical. It begins by telling us that the main deity is Amaterasu Ōkami and there is an image of some kind of her on the roof (at least I am guessing this is what it tells us: instead of a kanji there is a black box in the original and this is very confusing. For those of you who read Japanese the original is here). It goes on to tell us that as the shrine is  situated in the midst of dry field farming land the typical offerings  at the festival held in honour of Toyōuke-Ōkami, a grain-related kami, seeking an abundant harvest are are lettuce and daikon.