One of Yorimasa's grandchildren is Naritsuna OIKAWA (also known as. Izu-kanja Naritsuna or Saemon-no-jo Moritsuna, who is a younger brother of MINAMOTO no Munetsuna and MINAMOTO no Aritsuna); it is known that Naritsuna owned Oikawa-no-sho Manor in Kizaki-gun, Tajima Province, and started to use the name Oikawa clan.
遺児（孫）の一人に及川成綱（伊豆冠者成綱または左衛門尉盛綱とも称し、源宗綱・源有綱の弟に当たる）あり、但馬国木崎郡及川荘を領しはじめて及川氏を称したという。