Mary (Japanese メリー, Merii) is a young girl who Ib and Garry find on their way getting out of the gallery. Thought at first to be a live person from the gallery, Ib and Garry allowed her to join their party. Later in the game, Garry discovers that Mary is not truly a person, but a painting come to life by Guertena. At one point, she can be seen stabbing a mannequin head with a palette knife found in a room full of boxes. Ib and Garry abandon her as soon as they are reunited.
Mary has long blonde curly hair and blue eyes. She wears a one piece green dress with a white collar, white cuffs and a white lace at the end. She also has a tie around the collar similar to Ib's, only hers is blue in color. She also wears long black stockings and brown shoes. When seen in her portrait, she is weilding a yellow rose with two hands.
Mary has a very childish personality. She goes on about her favorite colors (red, blue, and pink) as Garry tries to warn her to stay safe. And she is also seen to be selfish, taking the candy that was meant for Ib in a certain ending. She repeats things (like her own name) and seems strangely excited about simple things, hinting that she isn't quite familiar with human norms before it is revealed that she is a painting. She can become quite violent when opposed, such as when she drops her yellow rose and Garry picks it up, and she orders him to not to touch it while brandishing a knife. This violent anger significantly arises in defense against her identity as a painting. In a certain ending, she can be destroyed if her painting is burned. After burning Mary's portrait, her sketchbook is open, revealing her true intentions. It is soon discovered that Mary had craved to leave the disoriented gallery, but in order to do so, "two people from the normal gallery must come and only one can get out". Mary then decides to target Garry in order to escape with Ib.