Against the Portuguese merchants who had exclusively gained profits from trade of raw silk, Ieyasu made merchants in Kyoto, in Sakai and in Nagasaki form itowappu nakama (the thread tally union) to diminish their profits.
また、ポルトガル商人に対しては生糸の独占的利益を得ていた為、これを削ぐことを目的として京都・堺・長崎の商人に糸割符仲間を結成させた。