The story picks up right after Shin Ultraman. Ultraman gives his life to Kaminaga, and Zoffy says humanity has been exposed to the universe. With aliens attacking one after another, biological weapons awakened by environmental destruction, chosen transmigrators, and Ultraman's return, what will become of the world?
Humans are creatures capable of carrying on through pain. Even when hardship strikes, surely they'll keep moving forward, one step at a time.