Japanese J7W Shinden
The Japanese J7W Shinden was truly one of the oddest, most futuristic, aircraft designs of the war. With its main wing mounted at the rear of the fuselage and a smaller wing to the front, the plane was powered by a big engine with a rear propeller and was designed to take on American B-29 bombers pummeling the homeland.
Early on, Japanese engineers had to figure out how to keep the engine from overheating, as it would tend to do that even on the ground. Eventually, they solved that problem and most of the others associated with the plane, but the war was over.
The plane was very heavily armed, carrying four 30 mm cannons. B-29 crews were spared the plane’s destruction, though, as it made only three test flights and never went into full production. The Japanese Navy was also developing a turbojet version of the plane but that never got off the drawing board.