Imperial Prince Masanari, the Imperial Prince of Emperor Gotoba and the younger maternal half-brother of Emperor Juntoku, became the adopted child of Imperial Princess Senyomonin Kinshi after his birth in 1200, and he was given the title of Imperial Prince when he was five.
後鳥羽天皇皇子で順徳天皇の同母弟・雅成親王は正治2年（1200年）の誕生直後、宣陽門院覲子内親王の養子となり、5歳の時に親王宣下を受けた。