After the death of Hideyoshi, he served Mitsunari ISHIDA and participated in the plot to overthrow Ieyasu as well as in the unsuccessful assassination attempt at Minakuchi on Ieyasu, who was on his way to subjugate Aizu.
秀吉没後は石田三成方に与し、家康打倒の謀議に参加、水口にて会津征伐へ向かう家康の暗殺を謀るも失敗した。