According to "Genpei Seisui ki" (Rise and Fall of the Minamoto and the Taira clans), Yoshinaka Minamoto's favorite concubines and female warrior Tomoegozen visited Kamakura after Yoshinaka7s death, Yoshimori told Yoritomo that he wanted to have a child with someone as strong as her, and Yoshihide ASAHINA was born after Yoshimori married Tomoe.
『源平盛衰記』では源義仲滅亡後、義仲の愛妾であった女武者巴御前が鎌倉へ下り、義盛があのような剛の者に子を産ませたいと頼朝に申し出て、巴を娶ったのち朝比奈義秀が生まれたとしている。