Yuki is practically bouncing off the walls after coming up with an idea to take a field trip outside the school grounds. Rii-san and Kurumi remind her that club members aren't supposed to leave the grounds, but Yuki's convinced that if it's a school-sponsored activity they won't be breaking the rules. Their destination: the mall! Take a stroll down memory lane, to the days before the group first met Mii-kun.

THEY flood into the school as if attempting to take shelter from the torrential rain. The power has been knocked offline. The School Living club room is under siege. Kurumi is unconscious after one of THEM bit her. All alone, Rii-san prepares to keep her promise. Meanwhile, Mii-kun prepares to go to the emergency shelter and find the vaccine, but the thought of having lost Taromaru to THEM drains her will to continue. Just as one of THEM reaches out to grab her, she's saved...by Yuki?!