Otomo Kentaro was the third son of the Emperor Hantei Kusada. He was fostered in 421 to the Scorpion Clan, to live at Shiro no Shosuro, where he learnt the ways of politics under the survey of the Gozoku. His whereabouts after the Gozoku was dismantled in 435 by his sister Hantei Yugozohime and the Scorpion Clan Champion Bayushi Minoko was killed, were unknown.