Whakaotihia te rerenga e whai ake nei: I te tau 1900, i whakatairangahia a Ōkubo ki te rangatira rangatira me te rangatira o nga kaimahi o te Inspectorate General of Military Training. I te Haratua 1902, ka riro ia hei rangatira mo te IJA 6th Infantry Division. I te Pakanga o Ruhia-Hapani, i whakauruhia te IJA 6th Infantry Division ki te Rererangi Tuarua o Hapanihi, engari i muri i te wehenga o te IJA ki te IJA, i whakauruhia te IJA ki te IJA.
Ko te Pakanga o Shaho i tukuna ki te Hapanihi Tuarua o Hapanihi i mua i te Pakanga o Mukden. Whai muri i te pakanga, i whakawhiwhia ia ki te Order of the Rising Sun, 1st class me te Order of the Golden Kite, 2nd class. I te Hōngongoi 1906, i whakawhitihia ia ki te whakahau i te IJA 3rd Division a i te Mahuru 1907 i whakaarahia ki te "kazoku" peerage me te taitara o "danshaku" (baron).