The protagonist Lu Xinghe accidentally traveled to the world of Ultraman Tiga. Because the "Light of the Star Core" left by Ultraman Noah was hidden in his body, he became the new giant of light "Ultraman Xinghan". He joins the victory team and fights side by side with Tiga (Dagu) and his teammates. He not only has to deal with the threats from monsters and cosmic people such as Gorzan and Melba, but also explores the origin of his own power of light, uncovers the deep connection between Noah and the ancient light civilization of the earth, and completes the transformation from an ordinary time traveler to the "successor of Noah's afterglow" in the battle to protect mankind.
