|Prototypes: 12 build
| First production version: fully retractable tailwheel,
two 7.7 mm (0.303 in) Type 89 machine guns in the wings and two synchronized
12.7 mm (0.50 in) Ho-103 machine guns in the forward decking. Capable
of carrying one 151 L drop tank or a light bomb.
|Second production fighter variant: Tailwheel retraction
mechanism was unreliable, the aircraft was modified accordingly. Two
12.7 mm (.50 in) Ho-103 machine guns replaced the wing 7.7 mm (.303
in) machine guns.
| The Hei was built in conjunction with the Otsu variant,
the wing machine guns were replaced by Mauser MG 151/20 cannons.
|Fighter variant with two fuselage mounted Japanese 20
mm Ho-5 cannon and two 12.7 mm (.50 in) wing mounted Ho-103 machine
|Had a pair of 20 mm cannons in nose to help it shoot
down bombers. Had a fixed tail wheel. Appeared in January 1944.
|Interceptor variant with 2 × 12.7 mm (.50 in)
machine guns and 2 × 30 mm (1.18 in) Ho-155 wing cannon.
|Experimental aircraft with evaporation system, as used
on the Heinkel He 100. It was the fastest Ki-61 built, achieving 630
|Prototype with 1500 hp Ha-140 engine and first flown
in December 1943.
|Pre-production version which reverted to the Ki-61-I-Tei
wing, a 220 mm (8.7 in) fuselage stretch, enlarged rudder, and Ha-140
engine; 30 built.
|Armed with 2 x 12.7 mm (.50 in) machine guns in the
wings and 2 x 20 mm cannon in the fuselage.
| Armed with 4 x 20 mm cannon.
|Prototype: This version had a cut-down rear fuselage
and a canopy design which was later used by the Ki-100-I-Otsu