Atsuko meets a mysterious cat on the street that suddenly begins following her. When Chuzenji-sensei sees it, he jokingly refers to it as a bakeneko (cat spirit), which makes the situation feel a little eerie. Later, when Chuzenji goes to an antique shop to buy a container for the cat, another mystery appears. The shop owner recently bought a backpack from a pawn shop, and strange rumors start surrounding the bag. Kanna and Chuzenji begin looking into the story, showing that the mystery around the backpack is connected to its previous owner rather than anything supernatural.