Gunparade March: Aratanaru Kougunka  

GPM, Gunparade March, Gunparade March - The New War Song, גאנפארייד, 건퍼레이드 마치 -새로운 행군가-, ガンパレード・マーチ -新たなる行軍歌-, 新结行军歌

The conflict started in 1945 at the conclusion of World War II when extraterrestrial beings invaded Earth's skies, necessitating humanity to confront an unprecedented danger. For the first time in history, individuals from all cultures united under a single flag. This war has lasted more than half a century and resulted in numerous casualties. The Japanese military now depends on young people like Atsushi Hayami and his high school classmates, known as Unit 5121, to continue the fight with the help of HWT humanoid combat machines and PBE bombs.