[Nyororin]

I think the interpretation of mainstream hero is skewed, to say the least. Pokemon, Dragon Ball, and the like are not "mainstream Japanese heroes". They`re popular characters, and nothing more. Sort of like Mickey Mouse, Spongebob, etc.

Toss out Yattaman, Ippatsuman, Kamen Rider, Ultraman, etc etc - those are the Japanese mainstream counterparts to the US Superman, Batman, and the like. And unless you are a fan of those to begin with, they`re not likely to be familiar to someone in the US. But I would guess that 9 out of 10 Japanese can sing the theme song for at least one of them.