A Japanese mystery bestseller, revolving around a series of unsettling floorplans, in which the reader is the detective – from the Youtube sensation Uketsu

A mysterious windowless room on a house's floorplan hints at a hideous secret. A young girl suspects that her cousin's seemingly accidental death was the result of a sinister family tradition. Can you uncover the dark secret of these strange houses? When you do, an unforgettable truth will be revealed.