
Don't friend zone him now. And how come he never came across a girl who likes shoujo manga in his whole life?

I think what's implied is that it's weird for the guy to like shoujo that much. Or that's how he feels. He's probably never met a woman who wanted to fangirl with a grown man over shoujo.
I have to say even in the US I've met few men even at cons who would admit to being hardcore fans of Sailor Moon or Cardcaptor Sakura. Most of the male anime fans I met liked things like Evangelion or Dragonballz.
Hentai Doctor