学園☆新選組！～乙女ゴコロと局中法度～

Synopsis

There is a girls boarding high school. It is known as a prestige high school, but the number of students are decreasing. Vice school principal suggests the school should become a coed school, but school principal refuses it. As a result, students divide into two groups.... Several days later, a boy is transferred to the school as a test. Like this, a battle for him breaks out.... (Source: Himeya Shop)

Anime adaptations