[DeepL Translation - needs review] Volume 1 Introduction: Lillian Girls' Academy is a private school for purely cultured maidens. In order to carry on the pure and correct school life, a system called "sisters (suru)" exists in the upper school. After the students pledged to become sisters through a ceremony in which they received a rosary, the older sisters would mentor the younger sisters. Yumi, who had not yet had an older sister when she entered the upper secondary school, was suddenly d...
As the title suggests, this is basically a retrospective, on the day before graduation. It's essentially collection of short stories, with a different PoV character per story, but a single, linear plot (no frame story necessary). Personally I was a bit bored at first, but the story got gradually more interesting, once it focused on the 山百合会 members again.
Pretty sure next volume is graduation. Hopefully I'll enjoy it more thanlast year's