After the failure of the G5N the Imperial Japanese Navy decided to try to build another four engine bomber. It was to be able to fly deep into Allied territory to carry out its missions.
In February 1943 Nakajima was asked to come up with a design for the bomber. The bomber was to have these specifications:
- Speed: 368 / 370 mph / 320 knots
- Bombs: 8,000 / 8,816 lbs / 4,000 kg
- Range: 4,600 miles / 4,605 statue miles / 4,000 nautical miles
- Climb to 26,000' / 26,245' / 8,000 m in 10 minutes
The G8N was an all metal design.
The wings were midway up the fuselage.
The G8N used a tricycle landing gear.
Armament was mounted in the sides, and in turrets located forward, in the back, in the belly, and in the tail.