I was reading Black Lagoon and realized that Lotton is a bit like a chuunibyou. He called himself "The Wizard" and he always wanted to make a cool entrance before a fight but usually got his ass kicked quickly. In my opinion, he's a chuuninbyou. But no one ever mention that he's chuunibyou.
(Or probably he's not chuunibyou after all, but keep that for another question.)
Being the earlier anime (Black Lagoon was aired in 2006 while Chuunibyou demo Koi ga Shitai! was aired in 2012) it got me thinking about whether the word "chuunibyou" actually originated from this anime. Or probably it was not just as popular as now.