The J.S.D.F. saw action in 1954, when the monster Godzilla first appeared and attacked Tokyo. Despite the J.S.D.F.'s efforts, they were unable to defeat the monster and Tokyo was devastated by Godzilla. In the following years, the J.S.D.F. would fight repeated battles against Godzilla and other giant monsters like Anguirus, Varan, Rodan, and Mothra. In order to combat these monster threats, the J.S.D.F. developed powerful new weapons, the most famous and effective one being the Maser Cannon.