It is said that this conversion took place as a result of the close relationship that Kita no Mandokoro's elder brother, Iesada KINOSHITA, had to both Kennin-ji Temple and Sanko Joeki, and Sanko Joeki leading Iesada's 7th son to enter the priesthood.
北政所の兄・木下家定は建仁寺及び三江紹益と関係が深く、家定の七男が三江紹益のもとで出家していることも、この改宗と関連すると言われる。