The superhero Starman is sent by the Emerald Planet to protect Earth from belligerent aliens from the Sapphire Galaxy. The Sapphireans (or "Spherions") kidnap Dr. Yamanaka and force him to use his spaceship against the Earth.

An evil brain from outer space unleashes monsters with deadly diseases on Earth with trying to conquer the universe. Superhero Starman must battle them all to save his planet.

Super criminals are planning to infiltrate Earth with mass nuclear destruction! Only Starman can defend civilization by thwarting evil!

A bunch of pernicious salamander men from the planet Kulimon in the Moffit Galaxy plan on taking over Earth by unleashing a lethal plague on mankind. It's up to valiant superhero Starman from the Emerald Planet to save the human race before it's too late.