Shin Hayata, a human who once hosted Ultraman, a powerful extraterrestrial being, has his past memories restored by the organization that aided Ultraman, the SSSP. His son, Shinjirou, shows incredible physical abilities, prompting the SSSP to consider him a potential successor to his father's role as Ultraman. After being attacked by an alien, Bemular, Shinjirou is rescued by his father, but not before the older Ultraman is severely injured. As a result, Shinjirou is encouraged to take on the role of the new Ultraman, working with the SSSP to protect the city from extraterrestrial threats.