Highlights from the interview with Tatsuya Ishihara in the volume 3 of Cloud_G magazine regarding Chuunibyou season 2:
-When the recording ended for the first season, we announced to the cast that "we're doing a second season."
-In the first season we made Rikka appear really pitiful, so we may treat her a bit better in the second season.
-It's still unknown how big of a presence Shichimiya will get in the second season.
-The four female leads have formed a solid group; I'm really worried about whether or not we can add a new actress to that group.
-Regarding who to play Shichimiya: That character hasn't been fully determined yet, so we don't have any idea.
-The Invisible Horizion probably still exists now, but instead of representing Rikka's father's death, it's not serious anymore.
-Dekomori's hair hasn't changed much. There may be a little bit changed.
-The other characters are fundamentally the same as before.
source:
http://0taku.livedoor.biz/archives/4507426.html