In AD 642, when his minister father SOGA no Emishi was in his late years, he took charge of national administration in place of father, when Emperor Kogyoku ascended the throne.
父の大臣・蘇我蝦夷の晩年の642年（皇極天皇元年）、皇極天皇の即位に伴い、父に代わって国政を掌理する。