A WINDOW TO CHILDHOOD

Exploration Stage: Mural House
From: Yuri
Description: Hopefully, by opening the box, we’ll figure out how to silence the fog and stop the townspeople’s madness. We need a clue to the square key area. Could you find it?
Completed: You found a clue to the box key - a board shaped like a window with characters painted on it. There’s a number two on the back. What does this have to do with the fog maiden?