Here's a
characters/seiyuus page for this show, with pics of 14 characters and their voice actors, and a bit of info about each voice actor.
Uchiyama Yumi (Kirishima) is just getting better and better. She's had lots of work this year. I'm very impressed with her as the teacher/baseball scout in
Diamond no Ace.
Yamamura Hibiku (Haruna) is the singer "hibiku," and sings the ED as part of Trident (with Numakura Manami and Fuchigami Mai). Fuchigami Mai herself is quite good as Iona. Probably better than she is as Petralka in
Outbreak Company.