Gundam 00 CG set from 2008 or so. EngDLsite name: "Congratulations, Second Season".

First character is Shirin Bakhtiar (I first thought it was a gendered bendered Tieria Erde, but notverycreative is likely right) then the usual girls from the 2nd season, in order of appearance: Feldt, Louise, Marina, Mileina, Nene, Wang, Soma and Sumeragi.

DL:
http://www.dlsite.com/maniax/work/=/product_id/RJ043435.html
http://www.dlsite.com/ecchi-eng/work/=/product_id/RE043435.html

Mugi:
?

Circle website:
https://twitter.com/saw_okinawa
http://section11.blog43.fc2.com/

E-hentai tip of the gallery:

8) You can buy GP for credits at The GP Exchange here: /exchange.php?t=gp

Ads:

We are always recruiting editors, translators and proofreaders for EHCOVE. If you are interested, come by the Cove of Translators in the forums and introduce yourself.-hentai.org/exchange.php?t=hath

I thought the first girl was Shirin Bakhtiar. F!Tieria has longer hair and it's a different color, isn't it?

Base +12, Red_Piotrus +53

Melonbooks DL - http://www.melonbooks.com/index.php?main_page=product_info&products_id=IT0000117904

DMM - http://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_019496/

Sowjun Pixiv - http://www.pixiv.net/member.php?id=559461

Sowjun Booth - https://motimoti3danbara.booth.pm/

Base +40, Red_Piotrus +53