The fourth season of Maria-sama ga Miteru. 
 
Life for the young women at Lillian Girls’ Academy couldn’t be more exciting! The Yamayuri Council is working on a theater production with the all-boys Hanadera Academy, and the school festival is quickly approaching. But Yumi’s duties pale in comparison to the task assigned to her by Sachiko: choosing someone as a petite soeur! Will she be able to handle the pressure of such a monumental decision, or will Yumi crumble under the weight of the Council’s — and Sachiko’s — expectations? 
 
(Source: Maiden Japan)