(This isn't all of the things that were covered in the volume, just the things I managed to write down.)
Mikoto can't bring himself to tell Waka he owns figures and plays dating sims. The girls try to figure out how to do a proper sleepover. The Drama Club has an improv day. Waka keeps randomly falling asleep, and Seo discovers her power over him. Kashima dresses more femininely, and Mikoto kind of hopes he'll get to see Hori acting jealous. Hori realizes Kashima is physically both his ideal guy type and his ideal girl. Bonus: the volume ends with comics featuring Chiyo's little brother meeting Nozaki. He misunderstood and assumed Nozaki was a model, so he's surprised at how ordinary Nozaki is.
As a Hori/Kashima fan, my favorite part of this volume was when Kashima dressed more femininely and Hori had his revelation. Will Tsubaki go anywhere with this? Who knows.
I liked getting to see Chiyo's brother, and there were a few good moments throughout the volume, but it's probably a good thing that this was the last Monthly Girls' Nozaki-kun volume in my pile, because I suspect I reached my burn-out point. It seems it's never a good idea for me to read too many 4-panel comedy volumes in a row.
(Original review posted on A Library Girl's Familiar Diversions.)