In addition, he had friendships with Soshitsu SHIMAI, Sotan KAMIYA and others of Hakata merchants and carried out trade between Japan and the Ming Dynasty in China as well as Japan-Korea Trade (however, they actually gained profit by trading with the Ming Dynasty in China and Korea until the late of 15th century and such trade declined after the Sanpo War while actual profit was transferred to local lords on Tsushima Island utilizing the nominal sign of the Otomo clan and wealthy merchants in Hakata).
また博多商人の島井宗室や神谷宗湛らと交友し、日明貿易や日朝貿易も行った（しかし実際に明国や朝鮮などとの貿易で利益をもたらしていたのは15世紀後半辺りまでで、三浦の乱を契機に少なくとも明・朝鮮との貿易関係は衰退し、名義上大友氏の看板を利用した対馬の国人や博多の豪商らに実利は移ってしまった。