Fifty years back, an otherworldly being of light, Ultraman, safeguarded Earth before disappearing. Shin Hayata, Ultraman's human vessel, lost all recollection of his heroic past. His son, Shinjirou, is born with exceptional strength and stamina. The SSSP, Ultraman's allies, unveils Hayata's history to him. Thus, his father resumes his Ultraman mantle, battling an alien threat named Bemular to protect Shinjirou. Left incapacitated after the fight, Hayata, Shinjirou steps up, grappling with his limits as he takes on the Ultraman legacy. Amidst alien perils and the absence of his father, Shinjirou questions the sacrifices he must make in aiding humanity.