The ichinomiya of Bizen Province

What the Japanese sources say

Three shrines are involved with the title here: Kibitsuhiko Jinja (吉備津彦神社), Isonokamifutsumitama Jinja (石上布都魂神社) and Ani Jinja (安仁神社). The Okayama Prefecture Tourism Federation’s own official page introduces the three side by side, so the authorities have not settled on one either.

For Ani Jinja, the Okayama Prefecture Shrine Agency says that it “first appears in the Shoku Nihon Kōki (続日本後紀) in 841 (Jōwa 8)” and is “recorded in the Engishiki Jinmyōchō (延喜式神名帳, the register of official shrines in the Engishiki, a law code completed in 927) as a myōjin taisha — the top grade of shrine — of Bizen Province”, and that in Meiji 4 it was made a kokuhei chūsha, a middle-ranking shrine supported by the state. It is the only myōjin taisha of the Engishiki in Bizen Province. The Okayama Prefecture Tourism Federation, however, writes “former ichinomiya of Bizen Province”.

For Kibitsuhiko Jinja, the Okayama Prefecture Shrine Agency calls it “the ichinomiya of Honshu, the ichinomiya of the land of Kibi”, and the city of Okayama calls it “an ippon ichinomiya directly under the imperial court”. It is the one most commonly treated as the ichinomiya today, and the largest in scale of worship.

Isonokamifutsumitama Jinja is a shrine listed in the Engishiki, but its old shrine rank was gōsha, a lower grade in that ranking, and it is not included in the “Bizen Province Sōsha shrine register (the nine shrines of special standing)” of the Bizen Province Sōsha-gū (the order of those nine being 1. Hachiman Ojima-gū, 2. Kibitsuhiko Jinja, 3. Ani Jinja, and so on).

— It looks like a collision between long-standing formal rank (Ani) and a later but powerful shrine (Kibitsuhiko) (this site’s reading). No primary source describing how Ani Jinja ceased to be the ichinomiya could be found.

Written from Japanese sources, each quoted. The Japanese page has the same discussion with the original wording.