The Type 96 light machine gun, an improvement over the previous Type 11 light machine gun was introduced into combat service in 1936, and quickly proved to be a versatile weapon to provide covering fire for advancing infantry. Both the Type 11 and Type 96 used the same 6.5x50mm Arisaka cartridges as the Type 38 rifle infantry rifle. The system had the advantage that any squad member could supply ammunition for the light machine gun; however, as the Japanese army was switching from the Type 38 rifle to the Type 99 Rifle which used a 7.7 mm cartridge, it was necessary to develop a new version of the Type 96 light machine gun that would also be able to use this larger caliber. The gun was produced at Kokura, Nagoya Arsenal and Mukden with total production about 53,000.
The Type 99 was basically the same design as the Type 96 light machine gun, and had a number of parts in common. However, it dispensed with the oiler and had better primary extraction, increasing reliability over its predecessors. Early models had a mono-pod at the stock and a flash suppressor on the muzzle, which was screwed onto a threaded portion of the gun barrel. A top-mounted curved detachable box magazine held 30 rounds, and the finned gun barrel could be rapidly changed to avoid overheating.
The Type 99 had a blade front sight and a leaf rear sight, with graduations from 200 to 1,500 meters, with a wind adjustment. A 2.5X telescopic sight with a 10 degree field of view could be attached at the right side of the gun. These were often issued to the best marksmen of the unit and occasionally employed like a sniper rifle. A standard infantry bayonet could be attached to the gas block below the barrel, but on the battlefield this feature proved inconsequential due to the weight of the gun and the fact that the blade was largely obstructed by the flash hider when it was fixed on the muzzle.