On 1 April 1943, Submarine Division 7 was reassigned to the 5th Fleet for service in the Aleutian Islands. The Japanese position in the Aleutians declined rapidly after the Battle of Attu began on 11 May 1943 with U.S. landings on Attu Island. On 21 May 1943, with the situation on Attu deterioriating — ultimately the battle there ended on 30 May 1943 with the annihilation of the Japanese garrison — the Japanese Imperial General Headquarters decided to evacuate the isolated garrison on Kiska. The evacuation began via submarine on 26 May 1943, with the submarines carrying evacuated personnel to Paramushiro in the Kuril Islands.