As Masako HOJO, the lawful wife of Yoritomo, noticed her pregnancy, Daishin no Tsubone was kept at a distance by Yoritomo who feared Masako's anger, and she bore a baby boy at the residence of Kageto NAGATO, one of his retainers.
しかし頼朝の正室・北条政子がこれに気づいたため、その怒りを畏れた頼朝によって遠ざけられ、家臣の長門景遠の宅にて男児を出産する。