After repairs were completed at Sasebo Naval Arsenal on 12 July 1942, "Mutsuki" was reassigned to the IJN 8th Fleet and participated in the bombardment of Henderson Field on 24 August 1942. During the Battle of the Eastern Solomons on 25 August 1942, "Mutsuki" was sunk in an attack by USAAF B-17 Flying Fortress bombers while assisting the damaged transport "Kinryu Maru", northeast of Santa Isabel island. "Mutsuki" took a direct bomb hit in her engineering section, killing 41 crewmen and injuring 11 more. "Yayoi" took on the survivors, which included her captain, Lt. Cdr. Kenji Hatano.