In May 1180, Yorimasa and his son Nakatsune made a plan with Prince Mochihito who was the third son of Cloistered Emperor Goshirakwa to destroy the Taira clan.
治承4年（1180年）4月、頼政・仲綱父子は後白河法皇の第三皇子以仁王と平家打倒を謀った。