The Iiyama Hachiman shrine is located in Fukawa, now a part of Nagato City, Yamaguchi, and is the main shrine of the area.
It was established in 772 and moved to its present location in 807. In the 15th Century the Mori Clan who had taken over the area from the Amago greatly expanded the shrine, and I suspect this is when it was turned into a Hachiman shrine
Being a Hachiman Shrine the main kami enshrined here is Ojin along with his father Emperor Chuai, mother Empress Jingu, and the 4th being Emperor Nintoku his son. usually the 4th kami at a Hachiman shrine is Himegami, Ojin's "wife".
Also enshrined here are 3 unamed female kami and I suspect they were the original kami of the shrine. Hachiman did not spread around the country until the samurai rose to power many centuries after the shrines founding.
I suspect that the 3 female kami may well have been the Munakata Sisters. As "daughters" of Susano, and hailing from north Kyushu, it is believed the Izumo area and north Kyushu were connected in an alliance and as northern Yamaguchi is halfway between those two places it would make sense.