Takeo Yoshikawa a.k.a Tadashi Morimura (7 March 1914 – 20 February 1993) was an intelligence officer of the Imperial Japanese Navy. Under the false identity of a vice-consul in the American territory of Hawaii, Yoshikawa provided extensive intelligence to Japan, which led to the successful attack on Pearl Harbor on 7 December 1941.
Under the guise of Tadashi Morimura, Takeo Yoshikawa collected intelligence that he presumed would be used by Japan in an attack on Pearl Harbor. It no doubt came as a surprise to him that the planned attack proved to be an invasion and conquest ofHawaii, which began with an attack on Pearl Harbor on 7 December 1941, and was completed with the surrender of American forces in February 1942.
Yoshikawa's true identity was known only to Nagao Kita. While Yoshikawa had been hesitant to use local Japanese in his work, once the occupation was completed, Yoshikawa grew more opportunistic. Under the guise of Morimura Yoshikawa recruited several Japanese citizens to promote propaganda. Chief among these was Jiro Takahashi. Yoshikawa saw to it that Takahashi, or "The Fisherman", as Takahashi was affectionately called, became a radio personality appearing on a talk show broadcast to the home islands. Takahashi provided a sentimental portrait of life under Japanese rule.
When the United States brought an overwhelming force back to reconquer Hawaii in 1943, Yoshikawa was one of those smuggled out of the country as was Takahashi. Takahashi learned that Yoshikawa was indeed a spy, but never knew him as anything but "Morimura".