The Fugaku had its origins in "Project Z", a 1942 specification for an intercontinental bomber which could take off from Japan, bomb the continental United States, and continue onward to land in Germany.
Both Nakajima and Kawanishi made proposals for the Fugaku. The Nakajima design had straight wings and contra-rotating four-blade propellers; the Kawanishi design had elliptical wings and single four-blade propellers. To save weight, some of the landing gear was to be jettisoned after takeoff. Both designs used six engines.
The project was cancelled in 1944 and the Fugaku was never built.
- Length: 46 m
- Wingspan: 63 m
- Height: 8.80 m
- Wing area: 330.00 m²
- Crew: 6 or more
- Powerplant: six Nakajima Ha-54 4-row 36-cylinder air-cooled radials, 5000 hp (373 kW)
- Empty weight: 42,000 kg
- Loaded weight: 122,000 kg
- Maximum speed: 780 km/h at 10,000 m
- Maximum Altitiude: 15,000 m
- Range: 19,400 km
- Armament: 4 × 20 mm cannon, 20,000 kg of bombs
- Ogawa, Toshihiko (1993). Nihon Kōkūki Daizukan, 1910–1945, Tokyo: Kokushokankōkai
Designation sequence: G5N – G6M – G7M – G8N – G9K - G10N