"Shōkaku" and "Zuikaku" formed the Japanese 5th Carrier Division, embarking their aircraft shortly before the Pearl Harbor attack.Each carrier's aircraft complement consisted of 15 Mitsubishi A6M2 "Zero" fighters, 27 Aichi D3A1 "Val" dive bombers, and 27 Nakajima B5N1 or −2 "Kate" torpedo bombers.