Yuuki Reiko, member of the Occult Club, barges into the Sket-dan's room holding a picture of one of Kaimei Academy's seven mysteries, the "Ghost of the Incinerator". The Sket-dan are on the case (mainly Switch), trying to find out the truth behind the picture, and getting Shimada Takako from the Newspaper Club mixed up in it, too...
You have attempted a serious 
crime against our students.
Han cometido un serio crimen contra 
una de nuestras estudiantes.
Habéis cometido un serio crimen contra 
una de nuestras estudiantes.
Vocês cometeram um crime
 grave contra nossos alunos.