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 declared a "sister" by Sachiko, a sophom...
This is my least favorite volume in the series so far. The first of 3 stories focuses on a plan to overcome Sachiko's 男嫌い condition, and is quite an enjoyable read, involving some of the 花寺 boys, Yumi, the 山百合会, etc. While I think Sachiko's 男嫌い thing (at least the way it's portrayed) is a bit of a stretch, it's put to great use as a plot device. I really loved seeing Yumi interact with one of the 花寺 kids in a way that doesn't involve them making terrible jokes about 柏木 and her (I felt soooooo bad for Yumi last volume). I also felt like we got to see a more proactive and mature side to her. It's great how she's developed over the last few novels.
The 2nd story could have been interesting, but was A - largely about a side character we haven't met, B - about 70% through the PoV of Mami (who is much less interesting than Minako). Instead of reading a story about her attempts to be a paparazzi reporter, I would have preferred to read the actual event she'd gone to report on. I can't say it was badly written - you could even argue the whole thing is a rather clever approach/twist - I just wasn't interested. I did really love the parts that involved Shimako & Noriko tho!
The 3rd story is just a short Yoshino-Rei omake that you can honestly completely skip. It wasn't that interesting. Either the author needed to fill pages, or just wanted to provide a tiny snack to Yoshino-Rei fans, I guess?
I'm glad 夏休み is over now, and looking forward to getting back to the main plot.