伊雑宮（いざわのみや） Izawa no Miya
Information from Ise Jingu
Isawa no Miya, sometimes called Izawa no Miya or Izougu, may hold a more important place in history than is commonly realized. Searches in English show that it is only one of 125 auxiliary shrines of the Ise Jingu. However, it may be the motomoto or original shrine of the Ise Shrines. The Nihon Shoki states that Yamatohime founded Isawa no Miya. Isawa no Miya is one of the Three Shrines of Ise.
Moreover, some very valuable historical documents have been found there. The priests and staffs of Isawa over the years must have preciously guarded these treasures.
Amateru of Hotsuma
As a Hotsuma researcher, Okunomichi is interested in places where Amateru lived. In Aya 27 we find Amateru receiving his final teaching at the deathbed of his grandfather, the sage Toyoke-sama. After a long period of mourning, Amateru returns to his homeland and announces a move to his new residence. This place is called Isawa no Miya. Here, Amateru taught the Way of Ise, Ise no Michi.
Sendai Kuji Hongi / Kujiki
This document was purportedly written by Prince Shotoku in 620 CE. In the year 1667 the Zen monk from Kyoto, Doukai Chouon accessed the Kujiki (31 volumes) at Ise Jingu. The complete copy of the 72-volume version was re-discovered in Isawa no Miya in 1667. In 1679 Chouon published the Kujiki-72, a copy of which is held by the National Diet Library. Interestingly, this copy, too, says that Isawa is the oldest of the Ise Shrines.
During the Warring States Period, Ise Jingu could not defend its three auxiliary shrines to the south and west of the main Naiku and Geku. In 1521 the Kuki clan seized Izawa Shrine; fortunately shrine staff had already hidden some of their treasured manuscripts. The Kujiki-72 was hidden at Ise (Isawa), Oomiya Jinja, and at Shitenno Temple.
Isawa no Miya
伊雑宮 いざわのみや Izawa no Miya, also Izounomiya 「いぞうのみや」, sometimes 「イゾウグウ」Izougu. Enshrined deity 天照坐皇大御神御魂 （あまてらしますすめおおみかみのみたま）Amaterashi masusume Oomikami no Mitama, alternately「瀬織津姫神天照大神分身在河」Seoritsu-hime-kami Amaterasu-Oomikami Bunshin Zaikawa.
Avery Morrow, Sacred Science of Ancient Japan, 2014