Dengeki Sentai Changeman

A hostile intergalactic force of aliens known as the Great Star League Gozma has conquered over a hundred planets across the universe. When Earth becomes the league's next target, the Japanese military ends up forming a new branch called the Earth Defense Force as a way to defend the planet from such a threat. Under the command of Commander Ibuki, various rookies enlisted for the Earth Defense Force undergo tough training in order to get enlisted for the newly established branch. (imdb)