Premise: The Rikugun Ki-202 "Shūsui-Kai" (Japanese: 三菱 Ki-202 秋水改 , translated as "Sharp Sword, improved") was a direct development of the German Messerschmitt Me 163 "Komet" rocket-powered interceptor aircraft. None were produced before Japan's surrender that ended World War II.
Hypothesis: The German Messerschmitt Me 163 "Komet" was used during World War II