Japan's Nakajima Ki-43 Hayabusa (peregrine falcon) fighter

The primary fighter for the Japanese Army in the early years of World War II was the Nakajima K-43 Hayabusa.

If there hadn't been such a rivalry between the Japanese Army and Navy, the Mitsubishi A6M Zeke might have become the main fighter for both services. The Army choose to use the Ki-43 even though it wasn't as capable.
Allied fighter pilots often mistaken the A6M for the Ki-43 in their combat reports. I can easily see why that would happen as the designs are very similar and under combat conditions positive identifications were near impossible.


Note: I often time think of World War II starting with the war in China, not the war in Poland.