After banishing the vengeful spirits from the staircase, Mayu, Yoshiki and Nana decide to try unlocking the music box Yoshiki found earlier. Mayu uses the Rusty Key she found on the podium of a classroom and unlocks it. Yoshiki then mentions that the box contains something but he can't squeeze his hand in there. Mayu suggests turning the box upside down and making the object fall down. After doing so the group acquire another key, this one belonging to the reference room.