Suginami Kuritsu Mahou Jogakuen Heiwa Iji-bu

The manga begins with a new school year at a school exclusively for girls with magic powers. While the academy covers elementary school, middle school, and high school, Kaede Shinohara is transferring as a first-year in high school. Under the school's "sisters" system, peacekeeping club president Mai Kiritani is assigned as Kaede's older sister and guides her around the school. Kaede ends up at the peacekeeping club, which turns out to be a hangout for students who aren't doing well in school.

(Source: ANN)

Included one-shots: Isha to Kangoshi, Steel Wedding