According to the "Jogu Shotoku Hooteisetsu" (Biography of Shotoku Taishi), Yamashiro no oe no o was a son of Umayato no toyotomimi shoutoku hoo, holly king, (此王有賢尊之心棄身命而愛人民也、後人与父聖王相濫非也) and his mother was daughter of SOGA no Umako, TOJIKO no Iratsume, his wife was Tsukishime no kimi, and his children were NANIHAMAROKO no miko, MAROKO no miko, YUGE no miko, SASA no himemiko, MISHIMA no himemiko, KAFUKA no miko and OHARI no miko.
『上宮聖徳法王帝説』では厩戸豊聰耳聖徳法王、聖王の児、山代大兄王（此王有賢尊之心棄身命而愛人民也、後人与父聖王相濫非也）とされ、母は、蘇我馬古叔尼大臣娘の刀自古郎女、妻は舂米王、子どもは難波麻呂古王、麻呂古王、弓削王、佐々女王、三嶋女王、甲可王、尾治王が生まれたとされる。