Hōjō Masako
Seriously ill, Yoriie proposed to name both his younger brother, Minamoto no Sanetomo, and his young son Minamoto no Ichiman to succeed him; the two would split power, governing separate parts of the country. It seemed natural to them that Hiki would then be the regent, even if unofficially, of young Ichiman. Hiki suggested to Yoriie that they arrange to have Sanetomo killed. Hōjō Masako, Yoriie's mother and wife of the first shōgun Yoritomo, allegedly overheard the conversation.