There is an episode in which, when Shogun Ietsuna died in 1680, the third successor, Prince Yukihito, was about to be captured by a chief minister, Tadakiyo SAKAI; it is one of the theories that emerged and became known, as both the Imperial Palace and Shogun tried to set up the story.
3代・幸仁親王は、延宝8年（1680年）に将軍家綱が死去した際、大老の酒井忠清によって将軍に擁立されようとした、とする宮将軍擁立説がある。