There had been an agreement between Cloistered Emperor Gomizunoo, then taking the virtual reins of the court, and the Edo bakufu (Japanese feudal government headed by a nominally emperor-appointed Shogun) that, if Emperor Reigen died before Fusako TAKATSUKASA delivered a son, the Emperor's oldest son Ichinomiya born to a daughter (an unidentified Chunagon Naishi (a maid of honor to the Vice-Councilor of State)) of Saneoki OGURA would inherit the throne, and this agreement had won consent of the Emperor and influential noble families including Sekkanke (families qualified for appointment as Prince Regent or Chief Advisor to the Emperor).
そこで当時院政を敷いていた後水尾法皇と江戸幕府との間で密かに万が一鷹司房子に男子が生まれないままに天皇が崩御された場合の時には小倉実起の娘（中納言典侍・実名不詳）が生んだ第1皇子である一宮が継承するという合意が出来ており、天皇や摂関家などの有力公家の合意を取り付けていた。