The two new characters are Kazumi (VA:Terakawa Ami) and Alice (VA:???)
It is said the theme of them two was black (Kazumi) and white (Alice). The VA for Alice will be audition and will start on the first February and her design might change after that.
It is said the new series in summer neither will be full gag (First and second season) nor full serious (alternative ova) but rather something in between.
http://www.animate.tv/news/details.php?id=1358939374