In the battle of Sekigahara, from his strong ties with the Toyotomi family, Ogo worked as a negotiator upon surrender of Otsu-jo Castle in Omi Province (represented by Takatsugu KYOGOKU, defense general) and of Tsu-jo Castle in Ise Province (represented by Nobutaka TOMITA, defense general).
関ヶ原の戦いでは豊臣家との縁の深さから、近江国の大津城（守将：京極高次）や伊勢国の津城（守将：富田信高）における開城交渉にあたった。