A young girl named Mariah dreams of having a puppy for Christmas, specifically a coveted dog named Princess. However, her parents are reluctant, believing she isn’t ready for the responsibility. Determined to prove them wrong, Mariah takes on the challenge of looking after her uncle’s dog, Jack, over the holiday season. Jack is unruly and mischievous, causing chaos everywhere he goes. Through a series of adventures and mishaps, Mariah tries to demonstrate she can handle taking care of a pet.

As Christmas approaches, Mariah faces additional challenges at home and school that test her patience and determination. Her family’s holiday preparations and their own concerns create obstacles to Mariah's plans, making her realize the importance of responsibility, love, and understanding. Through these experiences, she learns valuable lessons about what truly matters during the festive season. The journey brings Mariah and her family closer together, culminating in a heartwarming resolution that highlights the spirit of Christmas and mutual respect.