3rd April, 2011. At Tarachine International University, in classroom no. 409 of Block A, a professor was standing by the window when all of a sudden he was pushed from behind. The professor had fallen out of the window, into the heavy thicket below, and was therefore not seriously injured. Every year, without fail, a weird incident will take place at classroom no. 409, earning the room its nickname, "The cursed lab". The day after the incident, Kugawata Koichi was transferred over to the university, as the Associate Professor for the Literature Department...