On Astraea Hill, there are three girl schools; St. Miatre Academy, St. Spica Academy, and St. Le Rim Academy. In the corner of the site, there stands their common boarding house, "Ichigo-Sha".

Astraea Hill – it is a sacred place where men cannot enter…

Aoi Nagisa transferred to the 4th grade(*) of St. Miatre Academy by some reason. On the very first day, she met "Etoile", Hanazono Shizuma. Etoile is the leader of the whole students of the tree schools, and she was a girl of admiration. She has a large power and trust, at the same time, she must shoulder heavy responsibility and duty proportional to her power. Nagisa was fascinated by Sizuma’s beauty and she was frozen. On the other hand, looking into Nagisa’s face gently, Sizuma put her arms around Nagaisa’s shoulders and her face was approaching to Nagisa’s face…

(*) Because they introduce a system integrating junior and senior high school, the fourth grade corresponds to the first grade of normal senior high school.