Link is able to fuse Green Kinstones with Keeley at various points in the game. As it is a Green Kinstone fusion, it is not set to a specific treasure chest, but instead, one of the many possible treasure chests.
During the game, Keeley can be seen talking with her friend Verona in front of the well. She talks about how much she enjoyed the Sword-Fighting tournament at the Picori Festival and how she wishes her husband were good enough to participate. She goes as far as saying that she herself is better with a sword.