The story is set in a school where Guest is a new freshman. After arriving late to class, Guest is forced to stay behind with their teacher, Sukuna. The situation takes a dark turn when Guest, left alone to explore, discovers suspicious books about 'hollow purple' and 'domain expansion,' along with a sinister warning: a book titled 'Don't trust Teacher Sukuna.' Just as Guest is about to read it, Sukuna returns, forcing Guest to hide the book and pretend nothing is amiss. The narrative builds a tense, mysterious atmosphere around the seemingly helpful but dangerous teacher.