After conquering hundreds of planets, the Great Star League Gozma sets its sights on Earth. To defend it, the Japanese military forms an elite Earth Defense Force. Under Commander Ibuki, the force begins rigorous training. The five peoples is Changeman's transformers For their first act, the Gozma decide to eliminate those who pose the greatest risk of interfering with their invasion: the military. After a brutal day of training, the Earth Defense Force recruits are fed up with Ibuki's cruel ways and leave the training session. Soon afterwards, they are attacked by Gozma troops. Five surviving officers gather together, beaten and exhausted but refusing to retreat from the threat. The Earth trembles, empowering them with the Earth Force, giving them the power of mythological beasts and becoming the Changeman. With the mystical power of the Earth Force and military technology, the Changeman begin their war against Gozma.