Besides his wife, he had a favorite concubine named Oyuu (Yuu SUGIURA) and with her, he had Toshio OKUBO, the fourth son; Sukuma OKUBO, the sixth son; Shichikuma OKUBO; the seventh son; and Toshikata OKUBO, the eighth son.
大久保には妻の外におゆう（杉浦勇）という愛妾が居り、おゆうとの間に四男大久保利夫・六男大久保駿熊・七男大久保七熊・八男大久保利賢をもうけた。