According to the "Azuma Kagami," the situation is described as, 'It was announced that since Yoriie was seriously ill, his first son Ichiman, who was six years old, was hired and became the So-shugo (Master of Provincial constables) of Japan and So-jito (manager and lord of a manor) of the twenty-eight provinces in the Kanto region, while MINAMOTO no Sanetomo, who was twelve years old, became So-jito of the thirty-eight provinces in the Kansai region. However, Yoshikazu was against Sanetomo's succession and planned to kill him along with the Hojo clan' (Azuma Kagami on the section under August 27th (October 10th of the current calendar)).
『吾妻鏡』によると、「頼家が重病のため、あとは6歳の長男一幡が継ぎ、日本国総守護と関東28ヶ国の総地頭となり、12歳の源実朝には関西38ヶ国の総地頭を譲ると発表された。しかし実朝に譲られる事に不満を抱いた能員が、実朝と北条氏討伐を企てた」（8月27日条）。