Hayata Susumu, transported to the aftermath of the original Ultraman series, initially thought he was on the path to Ultraman, but a group of scientists suddenly appeared and captured him for experiments, claiming he was Ultraman's human host. Just when he thought he was on the path to Ultraman F, the scientists found nothing on him and had no choice but to let him go. As he decided to live as an ordinary person, a new crisis confronted him. Seeing the mechanical Ultraman created using human science, and King Joe closing in, Hayata Susumu realized: he was on the path to Gundam! This is a story about humanity protecting the Earth through its own efforts after Ultraman's protection is gone.

They say Echo is an evil star, a star that brings bad luck to relatives and friends.

Echo doesn't know the criteria for judging good and evil. He only knows that being held in someone's arms and comforted makes him feel warm, comfortable, and he wants to cry.

His life does not need to depend on others for its value!

Evil, good, everything is just a passing cloud. From that moment on, Echo's life is in his own hands!

"We've suffered, we've taken the blame, we've endured the grievances, and now you're telling me we're useless?!"

"If begging on my knees doesn't buy me a chance to survive, then I'll fight my way into a peaceful and prosperous world!"

"Today, even if I die, I will tear off a piece of your flesh!"