According to "Konjaku Monogatari Shu " (The Tale of Times Now Past), Inshi was born when her father Takafuji went to Yamashina for falconry, took shelter at the house of Uji Gunji (a local official in Uji) MIYAJI no Iyamasu, fell in love with Iyamasu's daughter MIYAJI no Resshi and had an affair with her.
『今昔物語集』によれば、父高藤が山科へ鷹狩に出かけた際雨宿りをした宇治郡司宮道弥益の家で、弥益の娘宮道列子を見初め一夜の契りでもうけたのが胤子である。