Gekkou Kamen is retired on the moon, so his trusty motorbike returns to Earth to find a new hero to take over the job of defending the Earth from alien invaders.

As the theme song denotes, no one knows who Gekko Kamen is. He is a lone figure dressed entirely in white, who mysteriously appears when danger is afoot.
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While he appears to be a regular human, he is exceptionally gifted in many areas including unarmed combat and gymnastics. He is an expert motorcycle rider and a superb marksman.<br><br>(Source: AniDB)

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