Shosaku's wife Shigeko was the oldest daughter of the second sosui of Mitsubishi Zaibatsu Yanosuke IWASAKI, which means that the MATSUKATA family was allied with the Mitsubishi founding family, IWASAKI family through marriage.
正作の妻・繁子は三菱財閥の2代目総帥・岩崎弥之助の長女なので、松方家は三菱の創業者一族・岩崎家と姻戚関係を結んだといえる。