Originally Posted by Paul
I think they're sung by Kotoko as well ( i havent checked, too lazy)
Well, i also recommend reading the Manga but its goes into a different story apparently.. and "WTF IS GOING ON" story line. There is also a Side Manga with Misaka or w/e he named was spelled (the lightning girl) which is basically her point of view during the anime/manga with cross scenes that you will notice.
They are sung by Kawada Mami. Maybe Kotoko as well, but the first opening is Kawada Mami.
And is the manga even good? I heard it is basd off of a light novel, which means the manga isn't the original, and all manga adaptations suck, so I would be cautious with the manga.