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.
The German Messerschmitt Me 163 "Komet" was used during World War II
It is not stated when that particular gun was developed. I think the system was fooled because I phrased it like an incorrect statement but switched a name from the context