Among the Taira clan was TAIRA no Yasumori who held a high-powered position, and a seemingly close relationship between Yasumori and the Nakahara family led to Yasuyori becoming a retainer of Yasumori in his teens.
平家一門の中で有力な地位にある平保盛という人物が居たが、保盛と中原家とは密接な関係にあったようで、康頼は十代で保盛の家人となっている。