Omiwa no Koremoto - The origin of Omiwa

...Their main family home was Ono-go, Ono County, Bungo Province (present-day Ono Town and Asaji Town, Ono County, Oita Prefecture). There is a legend of a divine marriage in which Ogami Koremoto, the ancestor of the Ono clan, is the son of the snake god Ubagake (Takachiho) Daimyojin, but there are two theories about their origins: one is that the Usa Ogami clan advanced into Bungo, and the other is that the Yamato Ogami clan settled in Bungo. The former theory states that the Ogami clan, a priest family of Usa Hachiman, advanced into Bungo after being chased by the Usa clan in the 11th century, while the latter theory states that it began when Korechika, the son of Bungo no Suke Ogami Yoshiomi, settled in the area as the local lord of Ono County....

*Some of the terminology explanations that mention "Okami Koremoto" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…豊後国大野郡大野郷(現，大分県大野郡大野町，朝地町)を本貫の地とした。大野氏の祖大神惟基を蛇神姥嶽(高千穂)大明神の子とする神婚譚をもつが，出自については宇佐大神氏の豊後への進出説と，大和大神（おおみわ）氏の豊後への土着説とがある。前者は宇佐八幡の神官家大神氏が11世紀に，宇佐氏に追われて豊後に進出したとし，後者は豊後介大神良臣の子庶幾（これちか）が大野郡大領として土着したのに始まるとする。…

※「大神惟基」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報