About Android school (all girl school?)
The students are the personification of Gadget/Device brands which use Android OS.
The School teacher is Google-Sensei
There also student (boys) from other school : Apple-Kun, RIM-Kun & Nokia-Kun

List of Cast and Character at ;
http://weekly.ascii.jp/elem/000/000/071/71299/

1.Adam Cupertino-Kun (Apple/Iphone)
2.Kyoto Seira-Chan (Kyocera)
3.Fuji Tooru-Chan (Fujitsu)
4.Matsushita Hana-Chan (Panasonic)
5.Kashio Nao-Chan (Casio)
6.Taoyuan Shiina-Chan (HTC)
7.Hayakawa Mirai-Chan (Sharp)
8.Shinagawa Sonia-Chan (Sony Mobile Communication)
9.Hoshino Una-Chan (Samsung)
10.Ei Shu Sue-Chan (Asus)
11.Motoki Laura-Chan (Motorolla)
12.Kinjo El-Chan (LG)
13.(Waifaa/Yuika) Yui Hana-Chan (Huawei)
14.Ho Ta (Panda) Sora-Chan (Pantech)
15.(Jong Shin/Hiiragi Sachi) Holly Miyuki-Chan (ZTE)
16.Kuroki Rimu-Kun (Blackberry RIM)
17.Hokuou Nokia-Kun (Nokia/Windows Phone)

Beside the above;
18.Google Sensei

Club (Japan Operator) :
19.D Club Coach (NTT Docomo)
20.A Club Coach (Au/KDDI)
21.S Club Coach (Softbank Mobile)
22.W Club Coach (Willcom)
23.E Club Coach (EMOBILE)

Official explanation in English, here => http://weekly.ascii.jp/elem/000/000/162/162166/