The two fleet carriers (Shokaku and Zuikaku) designed in 1936-37 were without question the most successful operated by the Imperial Japanese Navy; they had all the virtues and few of the vices of the Soryus and were, moreover, considerably larger, better armed and more heavily armoured, and could accommodate a larger air group. Their one principal defect was the light construction of the flight deck, aggravated by totally enclosed yet unprotected double hangars and unsatisfactory petrol bunkerage, but of course the proof of this was not available at the time of their conception.

Zuikaku 's career followed that of her sister-ship for the first six months of the war, her aircraft also being involved in the sinking of Lexington. She escaped damage in that action, and subsequently took part in the Aleutians operations. Zuikaku was seriously mauled during the Battle of the Philippine Sea, but her crew managed to overcome the fires which threatened to engulf the carrier. In October 1944, however, while assisting in feints to draw the US carriers supporting the Leyte Gulf landings (Cape Engano), she was hit first by one torpedo and later by a further six torpedoes and seven bombs and was sunk (25th).