"Hizen" supported the Japanese intervention in the Russian Civil War in 1918 and was often stationed in Vladivostok as a guardship. On 1 September 1921 she was reclassified as a 1st class coast defence ship and disarmed at Sasebo in April 1922 in accordance with the Washington Naval Treaty. She was stricken from the official naval roll on 20 September 1923 and sunk as a target ship in the Bungo Channel on 25 July 1924.