Maria-sama ga Miteru

At Lillian Academy, a private Catholic institution for girls, a tradition called the "soeur system" pairs younger students with older ones, fostering a sister-like relationship. The Yamayurikai, or Mountain Lily Council, serves as the student council and plays a central role in school life. Yumi, an unremarkable student, unexpectedly becomes involved with the Yamayurikai and their soeurs, particularly with Sachiko, a quiet, accomplished, and attractive student who is the object of Yumi's affection.