In her story, Mona leaves her house on an errand, leaving her Pets, alone. When she returns, she comes back to find that her animals have made a big mess around the house. She uses her boomerang to discipline her animals and force them to clean up their mess.
While controlling Mona, pressing makes her throw her boomerang, which stops her movement. The boomerang is controlled the same way as Mona is controlled, unable to stop and bouncing off surfaces. If the boomerang is returned to Mona, she will catch it and the player will regain control of her. The boomerang can also be recalled to Mona by pressing again. The boomerang can be used to interact with objects, and unlike Mona, the boomerang is invincible, allowing her to defeat enemies and reach faraway objects while evading hazards.