Secret and special weapons in Showa Japan

This article refers to plans for the incorporation and development of special or secret weapons in Imperial Japan during the first part of the Showa era, for the Second Sino-Japanese war and World War II, that were originally hidden from public knowledge to protect their efficacy. Weapons prohibited by the were of specific interest to Japan, since it was thought that if a weapon was banned then it must be particularly effective.

The United States and Germany are more famous for their development of special weapons, but Japan and Russia to a lesser extent both pursued weapons development.

The weapons developed by Japan included biological, chemical, and advanced conventional weapons. A diverse cross section of institutions and individuals in wartime Japan participated in various areas of development, such as The Munitions Ministry (Japan), the Tokyo Imperial University, the Riken (Japanese Institute of Physics and Chemical Research), the Black Dragon Society, the Mitsubishi business conglomerate, and the Nakajima Company. Military units involved included the Kempeitai, First Tachikawa Army Arsenal, Sagami Army Arsenal, and Yokosuka Naval Arsenal.

With the reinforcement of the defenses of the homeland, a strong desire arose within Imperial General Headquarters to improve the military situation by the invention of Special or Secret weapons for decisive combat. In order to apply science to military problems, from every aspect, IGHQ therefore appealed to scholars and technical experts for their co-operation.

Among the various assorted types of such weapons intended for decisive battle, the Japanese Army made efforts to put infra-red radiation to practical use. They tried to perfect heat-seeking bombs, in order to sink American troopships, with a 100% certainty of kill. This was expected to retrieve Japan's fortunes in one fell swoop.

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