Declassified documents

Declassified documents reveal that Japanese ultranationalists with ties to U.S. military intelligence plotted to overthrow the Japanese government and assassinate the prime minister in 1952. The scheme — which was abandoned — was concocted by militarists and suspected war criminals who had worked for U.S. occupation authorities after World War II, according to CIA records. The plotters wanted a right-wing government that would rearm Japan.
The CIA files, declassified in 2005 and publicized by the U.S. National Archives in January, detail a plot to oust the pro-U.S. prime minister, Shigeru Yoshida, and install a more hawkish government led by Ichiro Hatoyama. The CIA, in papers released under an act of the U.S. Congress to declassify documents related to Japanese war crimes, said the plotters were led by Takushiro Hattori, a former private secretary to Hideki Tojo, the wartime prime minister hanged as a war criminal in 1948.
Two CIA documents said the plot reportedly had the support of 500,000 people in Japan, and that the group planned to use a contact who controlled a faction inside the National Safety Agency — a precursor to the Defense Ministry — to help launch the coup. You can verify this information here:

http://www.archives.gov/iwg/japanese-war-crimes/introductory-essays.pdf