The 1912 Japanese construction program included two battleships. These were improved editions of the preceding Fuso class. The ships were named Ise and Hyuga and were slightly longer than the Fuso class but with the same beam. As with the Fusos, they carried their twelve 14-inch guns in six twin turrets but the pair amidships was arranged slightly differently. In common with other Japanese designs in the World War One period, the Ise class were faster than the battleships of other navies. The class had a maximum speed of 23.5-knots, while the USN contemporaries, the Pennsylvania and Arizona only had a speed of 21-knots. The RN 1912 program produced the fast battleships of the Queen Elizabeth class but the following 1913 program developed the Royal Sovereign class with a 23-knot speed. At the start of World War Two both the Fuso and Ise classes were considered too slow for participation in the main fleet actions. Accordingly, they were mainly regulated to home waters for a good portion of the war. However, the catastrophic aircraft carrier losses suffered by Japan at the Battle of Midway changed the future of the Ise class.
They were sent for a major refit in February and April 1943. To provide for greater fleet aircraft strength, the aft two turrets of the battleships were removed and a large hangar added upon which was a flight deck. The deck was too short for take-offs or landings so the aircraft would use a series of turntables and rails on the flight deck to stage for launching by the two large catapults at deck edge just forward of the flight deck. Originally it was planned to equip the ships with 22 Judy dive-bombers, which could be launched from the ships but would have to land on a true carrier or land base. In any event, they were never carried and the ships were equipped with fourteen Paul seaplanes. The original low angle 5.5-inch casemate mounted secondary guns were removed and eight twin gun 5-inch DP mounts were added to the decks forward of the flight deck. The light AA complement at the end of the conversion was fifty-seven 25mm guns. In June 1944 the AA armament was greatly expanded to 108 25mm guns. In September 1944 a further AA addition was made in the form of six 28-barreled 4.7-inch unguided rocket launchers. Both ships were part of Admiral Ozama’s decoy force at the Battle of Leyte Gulf and came through unscathed. Part of the reason for this is just their appearance upon firing their rocket launchers. Although no losses were recorded for USN strike aircraft to these rockets, the sheer pyrotechnic and smoke presented by the battleships upon firing the rockets, coupled with AA guns, caused many strike aircraft to steer clear. Both ships were sunk in shallow water by air attack in July 1945.
With N1203 Neptun produces the Ise in her Battle of Leyte Gulf appearance with the rocket launchers flanking the aft flight deck.