Monthly Girls' Nozaki-kun manga volume 13 features story and art by Izumi Tsubaki.

In the world of Nozaki and friends, pandemonium reigns supreme. While searching for the owner of a rather-unique-book, Hori stumbles across a shocking secret! At the same time, the life and times of Sakiko Yumeno are revealed online...And what’s this? Might Wakamatsu actually be able to stay awake the next time Seo sings?! But all of that pales in comparison when the true agent of chaos, Kashima, introduces a new partner-in-crime who wreaks havoc wherever they go...