In November of the same year, Iruka felt the need to kill Prince Yamashiro no Oe who had the right of succession to the Imperial Throne since he wanted Prince Furuhito no Oe to be the next emperor who was biologically related to the Soga clan.
同年11月、入鹿は蘇我氏の血をひく古人大兄皇子を天皇に為さんと欲し、そのためには有力な皇位継承権者である山背大兄王の存在が邪魔であると考えた。