From Moonphase:
Koizumi Risa: Okamura Akemi-san
Ootani Atsushi: Nagata Akira-san
Nakao Heikichi: Higashi Saori-san
Tanaka Chiharu: Kojima Kazuko-san
Suzuki Ryouji: Tsuda Kenjirou-san
Fukagawa Haruka: Onosaka Masaya-san
Kotobuki Seishirou: Takimoto Fujiko-san
Maiti: Suwabe Jun'ichi-san
Kanzaki Mayu: Matsuoka Yuki-san
Yoshioka Mimi: Araki Kae-san
Kohori Kazuki: Kamakari Kenta-san
Three Anipuri boys and a Tenimyu boy...!
Jomi Marquis: Saiga Mitsuki-san
Soldier Blue: Sugita Tomokazu-san
Keith Anian: Koyasu Takehito-sama
Fishis: Kobayashi Sanae-san
Seki Rei Shiroe: Inoue Marina-san
Sam Houston: Hatano Wataru-san
Harlei: Kosugi Juurouta-san
Rio: Namikawa Daisuke-san
Oh yeah, this anime suffers from "Gundam Naming Syndrome" which means you can't possibly predict the actual romanisation from the katakana and will change depending on the whims of subbers and posible official publication. But YES! I love it every time I see Koyasu-san's name appear on a cast list. Really, this is a great cast all round.