The Sanmu incident (三無事件, San mu jiken) was an attempted coup d'état in Japan that was foiled on December 12, 1961. During the raid undertaken by the National Police Agency, 13 conspirators were arrested.[1] It was the first coup attempt in post-war Japan. The only other attempt in this period, led by Yukio Mishima, would follow in 1970.
The stated goals of the group were to kill Prime Minister Hayato Ikeda, his Cabinet, and take control of the National Diet.[2] They hoped that this would prevent Japan from succumbing to a communist revolution. At the time of the arrest, the conspirators had already come into possession of uniforms and deadly weaponry, such as grenades and rifles.
Amongst the members were officers of the former Imperial Japanese Army, such as Major General Tokutaro Sakurai. Also involved were businessman Toyosaku Kawanami and former Manchukuo minister of economic affairs .[3] Another participant was Mikami Taku, a former Navy Lieutenant. He had previously been involved in a pre-war coup attempt in 1932, known as the May 15 incident, for which he was then imprisoned.