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...
But Reiko... She really got 
into my seven mysteries column.
Pero tú Reiko...
Pero tú, Reiko,
Mas a Reiko... Ela gostou de verdade 
da minha coluna dos sete mistérios.