In 645, he conspired with Naka no Oe no Oji and Ishikawamaro and assassinated SOGA no Iruka, who was in power at that time, at Asuka no Itabuki no Miya Palace; Iruka's father, SOGA no Emishi, was driven to commit suicide (Isshi Incident).
645年、中大兄皇子・石川麻呂らと協力して飛鳥板蓋宮（あすかのいたぶきのみや）にて、当時政権を握っていた蘇我入鹿を暗殺、入鹿の父の蘇我蝦夷を自殺に追いやった（乙巳の変）。