Ultraman Mebius is the protagonist of the eponymous series Ultraman Mebius. He was sent to Earth 25 years after Ultraman 80 to protect the planet from a new wave of monsters and aliens, many of which arrived due to Alien Empera's resurgence. During his tenure on Earth, he took the form of Mirai Hibino, and joined Crew GUYS.

He was the first Ultra Warrior to come from M78 in 25 years, after Ultraman 80. His mission was to protect humanity from being destroyed by evil monsters and invaders.

Along with him was another Ultraman from M78 called Ultraman Hikari. Hikari was a good Ultra but after a tragedy on Arb, he became the vengeful Hunter Knight Tsurugi. Having acquired the form from the living entity of Planet Arb, he became a selfish warrior bent only on revenge by killing Bogarl, the murderer of Arb, regardless of the lives it would cost.