His father Okiyuki was an ashigaru (common foot soldier) of the Kishu domain, but Okitsugu was appointed as a humble direct retainer to the shogun by the eighth Seii Taishogun (Barbarian-Subduing Generalissimo), Yoshimune TOKUGAWA.
父・意行は紀州藩の足軽だったが、第8代征夷大将軍の徳川吉宗に登用され小身旗本となった。