Looking at the first two Nyoin, Higashi Sanjoin's title was based on Higashi Sanjo-dono Palace, and Jotomonin's was based on Jotomon-dai (aka Tsuchimikado-dai; another name for Jotomon in Daidairi, the Greater Imperial Palace was "Tuchimikado," and the road that ran through it was called Tsuchimikado Oji or Jotomon Oji), both came from the ridai (palace outside the Imperial enclosure).
最初の二人の女院に即して見ると、東三条院の称号は東三条殿によって、上東門院の称号は上東門第（土御門第の別名）（大内裏の上東門は別名を「土御門」といい、そこに通じる道路は土御門大路または上東門大路と呼ばれた）によってと、いずれも里第に由来した。