However, the same year his retainer Murashige ARAKI (Because his wife was a daughter of Nagamasa IKEDA, he belonged to the Ikeda clan) and Tomomasa IKEDA (the legitimate son of Nagamasa) accepted a stratagem by Miyoshi Sanninshu and banished Katsumasa from Ikeda-jo Castle in cooperation with the Miyoshi clan.
しかし、同年に家臣の荒木村重（池田長正の娘を娶っていたため一族衆）と一族の池田知正（長正の嫡男）が三好三人衆の調略を受け三好家に寝返り、勝正は池田城から追放される。