When fighting with the army of bakufu, Soncho and his brother Nobuyoshi defended the Imoarai district, but upon the realization of their defeat, he cut himself loose from the battalion and was on the run.
幕府軍との戦闘においては、兄弟の信能とともに芋洗方面の守備に就くが、敗戦が明らかになると乱軍の中を脱出し行方不明となる。