As he had been working from an early stage as a close aide to the shogun, he handed over the position of the family head to his heir, Mochitsuna, and, in 1445, he was overthrown together with Mochitsuna by his son, Tokitsuna, who was supported by an opponent and committed suicide with a sword.
将軍の側近として早くから活動していたため、家督は嫡男の持綱に譲っていたが、1445年、反対勢力に擁立された子の時綱によって持綱と共に滅ぼされ自刃した。