After Toshiie died, when Mitsunari ISHIDA, one of Gobugyo (five major magistrates), backed Terumoto MORI up as their supreme commander and raised an army in 1600 against Ieyasu TOKUGAWA, who was one of Gotairo (Council of Five Elders), he and his elder brother Toshinaga belonged to the East squad and on their way to Sekigahara they caved Munenaga YAMAGUCHI, who was on the part of the West squad, in Daishoji-jo Castle in Hokuriku region.
利家の死後に慶長5年（1600年）に五奉行の石田三成らが毛利輝元を擁立して五大老の徳川家康に対して挙兵すると、兄・利長と共に東軍に属し関ヶ原に向かう途中、北陸の西軍方大聖寺城の山口宗永を陥れた。