Nobunaga. Ôishi clan of Ako (大石氏) – descended from the Fujiwara clan. The name Oishi comes from 'Oishi no sho' in Omi province. Famous for Ōishi Yoshio. Ôishi clan of Shinano (大石氏) – descended from the Fujiwara clan through the Numata clan. The name Oishi comes from 'Oishi go', in Shinano province. Ôishi clan of Musashi (大石氏) – descended from the Kiso clan (Seiwa Genji). Ōkōchi clan (大河内氏) – descended from Seiwa Genji. Ōta clan – descended from Seiwa Genji; famous for Ōta Dōkan. Ogasawara clan (小笠原氏) – cadet branch of Takeda clan descended from Seiwa Genji. Ōtomo clan (大友氏) – descended from Fujiwara Hokke; no direct relation to the ancient Ōtomo clan (大友氏) or Ōtomo clan (大伴氏); famous for Ōtomo Sōrin. Ōuchi clan (大内氏) – descended from Tatara clan and claim to descend from the royal house of Baekje. Rokkaku clan (六角氏) – cadet branch of Sasaki clan who descended from Uda Genji. Sagara clan (相良氏) – descended from Fujiwara Nanke. Saitō clan (斉藤氏) – descended from Fujiwara Hokke; famous for Saitō Dōsan. Sakai clan (酒井氏) – cadet branch of Nitta clan, by the Tokugawa clan descended from Seiwa Genji. Sakuma clan (佐久間氏) – cadet branch of Miura clan who descended from Kanmu Heishi. Sanada clan (真田氏) – descended from Seiwa Genji (disputed); famous for Sanada Nobushige who is more commonly known as Sanada Yukimura. Sanjō family (三条家) – descended from Fujiwara Hokke; famous for Sanjō Sanetomi. Sasaki clan (佐々木氏) – descended from Uda Genji. Satake clan (佐竹氏) – descended from Seiwa Genji. Satomi clan (里見氏) – descended from Seiwa Genji. Shiba clan (斯波氏) – cadet branch of Ashikaga clan who descended from Seiwa Genji. Shimizu clan of Mino (清水氏) – descended from Minamoto no Yorimitsu of the Seiwa Genji. Shimizu clan of Bicchu (清水氏) – descended from the Taira clan. Shimizu clan of Izu (清水氏) – descended from the Fujiwara clan. Shimizu clan of Dewa (清水氏) – cadet branch of the Mogami clan and through the Shiba clan from the Ashikaga clan (Seiwa Genji). Shimazu clan (島津氏) – also known as Satsuma Clan; descended from Seiwa Genji. Shinmen clan (新免氏) – also known as Shimmen clan; cadet branch of Akamatsu clan who descended from Murakami Genji. Shōni clan (少弐氏) – descended from Fujiwara Hokke. Sō clan (宗氏) – descended from Koremune clan. Sogō clan (十河氏) – descended from Emperor Keikō. Sōma clan (相馬氏) – cadet branch of Chiba