Kiyomori's adoption of Kunitsuna's son showed how greatly he trusted Kunitsuna, and Heike Monogatari (the tale of the Heike) described Kunitsuna as follows: "He is deeply involved with TAIRA Dajo-daijin (Grand minister of state) and he has great ambition."
子を清盛の養子にするなど、清盛から信頼され「平大相国とさしも契深う、心ざし浅からざりし人なり」（『平家物語』）といわれた。