Taking the opportunity presented by Ieyasu leaving to attack Aizu, Mitsunari ISHIDA rallied anti-Ieyasu daimyos (feudal lords) such as Yoshitsugu OTANI and Terumoto MORI and took up arms.
石田三成は家康が会津攻めに赴いたことを好機として、大谷吉継や毛利輝元ら反家康派の諸大名を糾合して挙兵した。