Ki-43 Hayabusa "Oscar" (Unusual Aircraft Collection)
An extremely rare Nakajima Ki-43 Hayabusa ("peregrine falcon", allied code name "Oscar") during the 1996 "Warbirds Over Wanaka" airshow in New Zealand.
The more well known Zero was a naval fighter, but the Hayabusa was a land-based Japanese army fighter. Both were powered by radial engines, and shared much the same design philosophy, being lightweight and maneuverable, but lacking armor and firepower. Only half as many Hayabusas were built as Zeroes, but the Hayabusa still shot down more aircraft than the Zero, mostly because it had more targets to shoot at and those targets were not as capable as the US naval fighters the Zero had to deal with.
Deliveries started in April of 1941 and the Ki-43 soon became the most important Japanese army fighter, gaining air superiority in the initial stages of the war in Malaya, the East Indies, Burma and New Guinea. Once the initial wave of advances subsided the Hayabusa found itself outclassed by allied aircraft, but it had to soldier on until the end of the war because there weren't enough superior replacement aircraft. Surprisingly the Ki-43 was used after the war, when captured aircraft were incorporated into the air forces of communist China, Taiwan, Indonesia and North Korea. Some captured aircraft were even used to a limited extent by the French fighting against communist rebels in Indo-China.