A sequel to the above, serialized in Koudansha's Monthly Young Magazine. Written by Ikoma (aka. Asao Yoshinori) and illustrated by Midorito Momoka (a joint pen-name of Midori & Momoka).
ステラ女学院高等科C3部[C³部] (Stella Jo-Gakuin Koutou-ka C³-bu [C-cube], Stella Women's Academy, High School Division Class C³)
A 2013 anime series by GAINAX. Its story is a bit different from the manga version.