Yasumaro's younger brother ISHIKAWA no Iwatari and his son ISHIKAWA no Toshitari became associated with the Southern House of the Fujiwara clan which was directly descended from Muchimaro by virtue of Masako's marriage to Fuhito.
その故を持って、その弟の石川石足と子の石川年足は、当時嫡流とされた武智麻呂を祖とする藤原南家と結びつくようになる。