Since his father, Kuraichi was appointed as Yagura-bugyo-kaku (Marshal of the Watchtowers) and served in the office of accounting in Kameyama Domain, Gentaro was raised in the expectation that he would be active in a business society.
父・蔵一は櫓奉行格に取り立てられ、会計方として亀山藩に仕えていた人物であったため、源太郎も経済界で活躍することを期待されて育った。