The left-wing Japanese novelist Wataru Kaji disappeared, leading to a government inquiry in which CIA involvement was investigated; Kaji stated he was kidnapped and held against his will by intelligence officers, which the United States denied.

Wataru Kaji was the nom de guerre for Mitsugi Seguchi, a Japanese writer, literary critic, and political activist.

The activities of the Central Intelligence Agency (CIA) in Japan date back to the Allied occupation of Japan. Douglas MacArthur's Chief of Intelligence, Charles Willoughby, authorized the creation of a number of Japanese subordinate intelligence-gathering organizations known as kikan. Many of these kikan contained individuals purged because of their classification as war criminals. In addition, the CIA organized and financed a Japanese intelligence gathering program, Operation "Takematsu", utilizing the kikan as part of an intel gathering operation against North Korea, the Kuril Islands, and Sakhalin. One of the kikan created, the "Hattori group", led by Takushiro Hattori, allegedly plotted to stage a coup d'etat and assassinate Prime Minister Shigeru Yoshida on account of his opposition to Japanese nationalism.