Seiwa Genji
The Ōta clan claimed descent from the Seiwa Genji via Minamoto no Hirotsune, a younger son of Minamoto no Yorimasa. A 5th generation descendant of Hirotsune, Minamoto no Sukekuni, established himself in Kuwada District of Tanba Province (present day Kameoka, Kyoto) and adopted the name of the Ōta "shōen" as his own.