The people of Koga-ryu were usually engaged in farming or peddling to collect information in various places and, once called, they went to the war fronts or the rear of the battlefields to engage in espionage.
普段は農業をしたり、行商をしたりして各地の情報を探る一方、指令が下ると戦場やその後方へ出向き、工作活動に励んだ。