of this work, she was fitted with external degaussing coils and additional armour for her barbettes. World War II During the war Mutsu saw limited action, spending much of her time in home waters. On 8 December 1941, she sortied for the Bonin Islands, along with Nagato, the battleships , , , and of Battleship Division 2, and the light carrier as distant support for the fleet attacking Pearl Harbor, and returned six days later. On 18 January 1942, Mutsu towed the obsolete armoured cruiser as a target for the new battleship , which promptly sank Nisshin. In June 1942 Mutsu, commanded by Rear Admiral Gunji Kogure, was assigned to the Main Body of the 1st Fleet during the Battle of Midway, together with Yamato, Nagato, Hōshō, the light cruiser Sendai, nine destroyers, and four auxiliary ships. Following the loss of all four carriers on 4 June, Yamamoto attempted to lure the American forces west to within range of the Japanese air groups at Wake Island, and into a night engagement with his surface forces, but the American forces withdrew and Mutsu saw no action. After rendezvousing with the remnants of the striking force on 6 June, about half of the survivors from the sunken aircraft carriers of the 1st Air Fleet were transferred to Mutsu. She arrived at Hashirajima on 14 June. On 14 July, Mutsu was transferred to Battleship Division 2 and then to the advance force of the 2nd Fleet on 9 August. Two days later, the ship departed Yokosuka accompanied by the cruisers , , , , , and , the seaplane tender , and escorting destroyers to support operations during the Guadalcanal Campaign. They arrived at Truk on 17 August. On 20 August, while sailing from Truk to rendezvous with the main body of the 3rd Fleet, Mutsu, the heavy cruiser Atago, and escorting destroyers unsuccessfully attempted to locate the escort carrier in response to a flying boat detecting the American ship. During the Battle of the Eastern Solomons on 27 August, Mutsu, assigned to the support force, fired four shells at enemy reconnaissance aircraft, the first and only time her guns were fired in anger during the war. Mutsu returned to Truk on 2 September; a group of skilled AA gunnery officers and men were detached to serve as instructors to ground-based naval anti-aircraft gunners stationed in Rabaul. During October Mutsu off-loaded surplus fuel