The Jinshin Yakujo, which was a peace treaty ending the Sanpo War, forced the So clan to restrain the dispatching of trade ships so as to force the reduction of toshu saikensen (Annual Tribute Ships to Korea from the Lord of Tsushima, and trade ships annually dispatched from Tsushima for trading and diplomatic visits) from 50 to 25, and to stop dispatching saikensen under the name of many shimuchowe (Japanese people other than the residents of Tsushima).
三浦の乱の講和条約である壬申約条では、島主歳遣船（対馬から通交のため毎年派遣される貿易船）を50隻から25隻に削減、多くの深処倭（対馬以外の日本人のこと）名義の歳遣船の停止等、宗氏に通交の抑制を強いるものであった。