"Haruna" fought in almost every major naval action of the Pacific Theater during World War II. She covered the Japanese landings in Malaya (in present-day Malaysia) and the Dutch East Indies (now Indonesia) in 1942 before engaging American forces at the Battle of Midway and during the Guadalcanal Campaign. Throughout 1943, "Haruna" primarily remained at Truk Lagoon (Micronesia), Kure Naval Base (near Hiroshima), Sasebo Naval Base (near Nagasaki), and the Lingga Islands (in present-day Indonesia), and deployed on several occasions in response to American carrier airstrikes on Japanese island bases. "Haruna" participated in the Battle of the Philippine Sea and the Battle of Leyte Gulf in 1944, engaging American vessels in the latter.