The protagonist Ah Wu, who grew up in the forest, faces many troubles after returning to city life due to difficulty adapting. At this time, two old friends with superpowers—Raccoon Shadow and Blue Bun—appear. However, they are not here to help Ah Wu adjust to city life but to entrust him with the mission of protecting the city. It turns out that a small mouse, using extraordinary intelligence, has created giant monsters that are rampaging through the city, seizing food and resources. For the safety of the city, Ah Wu resolutely accepts the mission, transforming into Armor Beast Superman to teach the troublemaking monsters a lesson. Through countless trials and challenges in battles against the monsters, Ah Wu gradually matures. One day, he will adapt to city life and become an outstanding guardian of the city.