Yoshikazu HIKI was an adopted son of Hikinoama who was a wet nurse of MINAMOTO no Yoritomo and his wife was a wet nurse of Manju, the first son of Yoritomo (who was to become MINAMOTO no Yoriie), so he gained Yoritomo's trust and became one of the senior vassals.
源頼朝の乳母の比企尼の養子であり、妻が頼朝の嫡男万寿（後の源頼家）の乳母ともなった比企能員は、頼朝に信頼され有力御家人となった。