On 14 July 1942, Submarine Division 33 was reassigned to the 5th Fleet for service in the Aleutian Islands, where the Aleutian Islands campaign had begun in June 1942 with the Japanese occupation of Attu and Kiska. At 16:00 on 24 July 1942, "Ro-63", "Ro-64", and "Ro-68" departed Yokosuka bound for Paramushiro in the northern Kurile Islands, An outbreak of food poisoning among her crew forced "Ro-64" to turn back, but "Ro-63" and "Ro-68" pressed on, reaching Paramushiro on 29 July 1942. They put to sea again on 31 July 1942 to head for Kiska, arriving there on 4 August 1942. Thereafter, they was based there along with the submarines , "Ro-61", "Ro-62", , and .