While pursuing a mysterious blue sphere, Shin Hayata, a member of the Science Special Search Party (SSSP), collides with a red sphere in the skies above Ryugamori and crashes. Inside the red sphere is "Ultraman," an alien from Nebula M78. Deeply remorseful for unintentionally inflicting fatal injuries upon Hayata, Ultraman shares his own life force with him, vowing to fight side by side to protect the Earth.
