Araki was born in Komae, Tokyo; his father was an ex-samurai retainer of the Hitotsubashi branch of the Tokugawa family. Araki graduated from the Imperial Japanese Army Academy in November 1897, and was commissioned as a second lieutenant in June of the following year. Promoted to lieutenant in November 1900 and promoted to captain in June 1904, Araki served as company commander of the 1st Imperial Regiment during the Russo-Japanese War.