​Reiko and Shintaro, tasked with festival preparations, stumble upon a student offering them a unique drink. Unexpectedly, the drink arouses Reiko, leading her to coax Shintaro into a dark, maze-like classroom. In the midst of their encounter, they separate. Reuniting, Reiko realizes that Shintaro wasn’t the one who found her; he had left the room. Concerned about Reiko’s unusual behavior, Shintaro seeks assistance from Misaki, another student council member. Misaki suggests that Reiko may be exhausted from festival preparations, prompting the trio to visit an amusement park. However, Misaki mysteriously disappears, and Reiko receives a shocking image on her phone. The image reveals the unfortunate fate of Misaki, leaving Reiko and Shintaro in shock.​