C³-bu

The C³-bu (sometimes Stella C³-bu) franchise that includes 2 manga:
 * 1) Tokurei Sochi Dantai Stella Jogakuin Chūtō-ka C³-bu set in middle school
 * 2) Tokurei Sochi Dantai Stella Jogakuin Kōtō-ka C³-bu set in high school

The second (Koto-ka, high school) series was adapted into an anime and its official English title is Preferential Measure Organization Stella Women's Academy, High School Division Class C³. Also shortened to  Stella Women’s Academy, High School Division Class C³, which is still pretty long. Class C³ would be the equivalent of the Japanese shortening.

Plot

 * Chuto (2010): Students in the "C³" club at the middle school division of Stella Women's Academy participate in military survival games.
 * Koto (2012): Yura Yamato has just arrived at the high school division of Stella Women's Academy, when Sonora Kashima invites her to join a club called "C³".

Other Sources
ANN:
 * no page for the 2010 middle school manga
 * 2012 high school manga
 * 2013 high school anime

MAL:
 * 2010 middle school manga
 * 2012 high school manga
 * 2013 high school anime

Other Wikis

 * C3-Bu