At this point, the Joseon dynasty wanted to cull society of its multiethnic character, which had been the norm during the Goryeo period (918 - 1392), and achieve a monopoly over trade profits by bringing trade under government control, so they requested that the Muromachi bakufu, the tandai (military commissioner) of Kyushu, and Sadashige SO, the de facto ruler of Tsushima island, bring both Wako activity and private trade under control.
そこで李氏朝鮮は高麗時代からの民族雑居状態の解消と、官営貿易で利益を独占する事を望み、室町幕府や九州探題、対馬の実質的な支配者である宗貞茂に対して倭寇および私貿易の取締りを要求した。