When the Otomo clan was defeated in the Battle of Mimi-kawa and the Shimazu clan gained power, Soshitsu who was close to the Otomo clan became afraid that his privileges would be taken away by the Shimazu clan so that he met the then ruler of the country Nobunaga ODA to gain protection from him.
耳川の戦いで大友氏が没落し、代わって島津氏が台頭してくると、大友氏寄りの宗室は自身の特権が島津氏に奪われることを危惧して当時の天下人・織田信長に謁見して、その保護を得ようとする。