In a bustling coastal metropolis, the ordinary life of high school student Lin Yu is turned upside down. He discovers a mysterious device emitting blue light in a park, while Zhang Yao, Chen Feng, Zhao Yang, and Su Yue each obtain similar devices. A mysterious voice tells them they have been chosen to become the next generation of Armor Heroes. The forces of darkness are about to return, and the safety of the city rests in their hands.
They show what they can do at an abandoned factory and successfully drive back the shadow creatures, only to be warned by a mysterious black-robed figure. After the battle, they decide to investigate the truth. They discover that the city's many strange occurrences are connected to an attack by the forces of darkness years ago, and that the seal seems to be weakening. To reinforce it, they must find five mysterious gems. The forces of darkness send out even more powerful monsters to stop them, and a new battle is about to begin.
