There is no real evidence as to how and when the Seiso-Shirayama Jinja was founded but the circumstances and timing are generally assumed to be the same as those for the Ōmiya Hachiman-Gū. The jinja's own information board and the history/culture page of the Suginami-ku home page discuss local place names rather than the particular history of the shrine, and what follows is taken from those two sources. It was the village shrine for the Shirahata (白幡) section of the old Seiso (成宗) village; the Shirahata name was taken from Minamoto Yoriyoshi's experience on the road to Ōshu. The existence of Seiso itself is attested to in a text published in 1559. Before being taken under the direct control of the Bakufu in the Edo Period, Seiso had been administered by the Okabe Clan (岡部氏), themselves Hatamoto, (direct retainers of the Tokugawa Shōguns). The Shirayama Jinja name comes from the Shinpen's entry for Higashitama-gun, where the existence of a Shirayama Jinja in Seiso village is noted. What was Higashitama-gun is now part of Nakano-ku and Suginami-ku. During the Edo Period,
(Note: numbers in parentheses after kami names
refer to position in How Many Kami table)
From Merged Shrines
Mitake Jinja 御嶽神社
Inari Jinja 稲荷神社
Kotohira Jinja 金刀平神社
Dairokuten Jinja 第六天神社
Earliest mention of: Unclear
Annual Festival: September 14
Hoshoji (宝昌寺) served as the jinja's betto-ji, and is still to be found slightly to the north at Naritanishi 3-3-30.
#2 in the Zenpukuji River Jinja Walk, about 600 metres from Ōmiya Hachiman-Gū. The shrine is quite small so not that much to describe, note that the four in-ground shrines identified in the box above are all combined in the one building.