"Taiyō", as the first ship completed, had an armament of six single 45-calibre 10th Year Type anti-aircraft (AA) guns in sponsons along the sides of the hull. The guns had a maximum elevation of +75° which gave them a range of and a ceiling of . They fired projectiles at a rate at 10–11 rounds per minute at a muzzle velocity of . Her light AA consisted of eight license-built Type 96 in four twin-gun mounts, also in sponsons along the sides of the hull. They fired projectiles at a muzzle velocity of ; at 50°, this provided a maximum range of , and an effective ceiling of . The maximum effective rate of fire was only between 110 and 120 rounds per minute due to the need to frequently change the fifteen-round magazines.