NATIONAL KID appears to be a popular superhero TV Series from the late 50s early 60s and an equally popular Manga from the time. He was inspired either by the George Reeves SUPERMAN Tv Show or the Adam West one depending on who is right.
I found a bookstore that was carrying reprints of his original Manga adventures and the covers alone look wild. The character was created as a business mascot (electric company?) and given his own book and show.
In the TV Series he seems to be played by a much older guy than the title would imply. But still he's a sort of interesting hybrid between Superman, Batman and Flash Gordon. He seems to be a bit on the obscure side.
GEKKO KAMEN on the other hand is likely the biggest Japanese costumed hero I'd never heard of. Star of his own late 50s TV Show he's Japan's first serialized adventure series.
Clad in a turban which covers his whole face and a pair of sunglasses that complement his two automatic pistols this daredevil rides around on a motorcycle and dispatches some of the craziest bad guys short of Ultraman.