In September 1598, upon the death of Hideyoshi, he followed his opposition policy against the Bunchi faction including Mitsunari and approached Ieyasu TOKUGAWA, one of Council of Five Elders, and married the adopted daughter of Ieyasu (daughter of Masanao HOSHINA).
慶長3年（1598年）8月、秀吉が死去すると、三成ら文治派との対立路線から五大老の徳川家康に接近し、家康の養女（保科正直の娘）を正室に迎えた。