Araki was born in Komae, Tokyo; his father was an ex-samurai retainer of the Hitotsubashi branch of the Tokugawa family.
Promoted colonel on July 24, 1918, Araki served as a Staff Officer at Expeditionary Army Headquarters in Vladivostok between 1918-19 during the Japanese Siberian Intervention against the Bolshevik Red Army, and was commander of the IJA 23rd Infantry Regiment.