Hypothetical up-armored interceptor version - Japan, September 1945.
Powered by a 2200 hp turbo-supercharged Mitsubishi Ha-43 engine including an inter-cooler, with a maximum speed of 648 km/h.
The armament consisted of six 30 mm (1.20 in) Type 5 cannons, four wing-mounted & two oblique fuselage-mounted.
Full-scale mock-up built, but no prototype.

Hypothetical improved version - Japan, October 1945.