The Ki61 was quite a departure from the other Japanese fighters of its day. Most notably it was designed around a license built DB601 liquid cooled V12 making it the only non-radial powered mass produced fighter in the Emperor's inventory. As is generally known, the Allies code named it the Tony under the false impression that it was not of Japanese design due to its resemblance to Italian fighters.

Entering service in 1943, performance was considered quite good although reliability was not impressive. It served to the last days of the war; ~2500 were produced.