Hōjō Tokimasa
In 1203, the 21-year-old Yoriie became extremely ill and weak, and Tokimasa produced a plan whereby Japan would be divided between Minamoto no Sanetomo and Minamoto no Ichiman, Yoriie's son, and very close to the Hōjō, who was planning to become the next "shōgun". Yoshikazu began to suspect something based on the attitude of Tokimasa, Masako, Ichiman, and Sanetomo, and hatched a plot to capture and assassinate Hōjō Tokimasa.