The A6M3 mod. 22Kō, designated as the Type 0 Carrier-based Fighter Model 22A (零式艦上戦闘機二二型甲), was a minor modification of the A6M3 mod. 22, having the same fuselage, engine, and wings with the difference being a switch of main guns. The Model 22Kō comes with 20 mm Type 99 Model 2 cannons instead of Model 1.

It was introduced in Update 1.37. The Model 22Kō has a different main armament than the previous one, which makes a significant difference in combat. The main improvements of the Type 99 Model 2 over the Model 1 are a longer barrel, a longer chamber, and a longer cartridge, which increase the muzzle velocity from 600 m/s to 750 m/s. The Model 22Kō performs similarly to other models with full-sized wings, but has a more accurate and higher velocity main armament, which has less bullet drop and hits targets quicker, delivering the same lethal ammunition.