 In early 1945, the sisters were rearmed when their 8-inch guns were replaced by four 12.7 cm (5.0 in) Type 89 dual-purpose guns in two twin mounts and four of their remaining 6-inch guns were removed. When firing at surface targets, the Type 89 gun had a range of 16,100 yards (14,700 m); they had a maximum ceiling of 30,970 feet (9,440 m) at an elevation of + 90 degrees. Their maximum rate of fire was 14 rounds a minute, but their sustained rate of fire was around 8 rounds per minute. Their light anti-aircraft armament was significantly reinforced by the addition of 9 (Iwate) and 14 (Izumo) license-built Hotchkiss 25-millimeter Type 96 light AA guns in single, double and triple mounts and two 13.2-millimeter Hotchkiss machine guns in single mounts. The 25 mm (0.98 in) weapon was the standard Japanese light anti-aircraft gun during World War II, but it suffered from severe design shortcomings that rendered it a largely ineffective weapon. The twin and triple mounts lacked sufficient speed in train or elevation; the gun sights were unable to handle fast targets; the gun exhibited excessive vibration; the magazine was too small and, finally, the gun produced excessive muzzle blast. The weapon had a maximum range of 24,600 feet (7,500 m), but effective range was only about 4,900 – 9,800 feet (1,500 – 3,000 m).
