Ki-65 is a prototype warplane that was made in 1940 in Japan. Its Japanese nickname is "Ko-bai" means scarlet apricot . Allied reporting name is "Scarlet ".
Water-cooled engine was adopted due to the shortage of fuels.
Its shape was designed after the preceding warplanes He112 and He100 imported from Germany.
State-of- the- art technologies were adopted such as SuperCharger ,Contra-rotating propellers and Turbo charger to over insufficient power of the engine .

The results of test flight was very good. But they are too expensive to produce so many. Japanese navy's report allegedly claims that Ko-bai succeeded to shoot down a B-29 super fortress thanks to its efficiency of high altitude flying at Great Tokyo Air Raid in 1945 .