The “JAPAN” clasp was designed for wear on the Army of Occupation Medal (AOM), which was established by the War Department in 1946; the clasp is currently authorized only in Army and Air Force medal regulations. The
AOM was awarded to Servicemembers who logged 30 consecutive days of duty at a normal post (those serving in special assignments such as inspector, visitor, escort, etc. or who were on temporary duty were not eligible) between 3 September 1945 and 27 April 1952, but in some cases the Servicemember must have also qualified for the Asiatic-Pacific Campaign Medal.
To wear the “JAPAN” clasp, Airmen and Soldiers must have earned the
AOM for service in Japan or Korea. Service areas for Japan included the four main islands (Hokkaido, Honshu, Shikoku, Kyushu), the smaller islands surrounding them that form the Japanese homeland, the Ryukyu Islands, or the Bonin-Volcano Islands. However, service during the six months immediately following the Japanese surrender (3 September 1945 – 2 March 1946) was counted toward the medal requirements only if the candidate had been awarded the Asiatic-Pacific Campaign Medal for service before 3 September 1945.
Occupation service in Korea between 3 September 1945 and 29 June 1949 could also qualify an Airman or Soldier for the AOM, but the same caveats regarding the six months of service following the Japanese surrender is applied here as well. Also, any service that was used to meet the eligibility requirements for the Korean Service Medal was not counted toward eligibility for the AOM.