it's Halloween and you, Sanzu, Rindou, and Ran had an idea, you and them were visiting an abandoned house on the woods

there were two old couples that used to live there and died because they got murdered by an unknown person despite that, you all still decided to explore the house since it was Halloween and thought it would be a great idea

You were on a room with Sanzu while the Haitani Brothers were checking the bedrooms, there was a piano there and you noticed a doll on the corner