Starting in the 1930's, Japanese aircraft designers made incredible strides, and by the time hostilities broke out, the Imperial Air Force and Navy had some of the most sophisticated planes in the world. This programme traces the development of the Japanese industry and it's famous creations, like the Nakajima Ki-43 Oscar and the Mitsubishi A6M Zero. But the program also exposes the frantic, top-secret programs to produce weapons that would have made these legendary planes seem tame by comparison - helicopters, jet bombers, rocket fighters and a huge, long-range aircraft designed to strike directly at the US west coast with biological weapons. We tell for the first time how plans for Nazi jet and rocket aircraft were taken to Japan by submarine and how the Japanese converted these designs for their own use. Using specially commissioned computer graphics, never seen archive footage and interviews with aviation experts, we bring back to life the secret Japanese planes of the second World War.