Ho-203 was a Japanese autocannon that saw considerable use during World War II. It was a long-recoil automation of the Year 11 Type direct-fire infantry gun. It was fed by a 15-round closed-loop ammunition belt. It was used only as the nose gun of the Ki-45 KAI heavy fighter, the anti-bomber workhorse of the Imperial Japanese Army.
- Caliber: 37 mm (1.45 in)
- Ammunition: 37 x 112R (475 g)
- Weight: 90 kg (200 lb)
- Rate of fire: 120 rounds/min
- Muzzle velocity: 570 m/s (1,870 ft/s)