The series is also based on Casey and Derek's rivalry.
The family is revealed to live in London, Ontario, Canada, when George is reading a newspaper titled London Chronicle in episode "Don't Take a Tip From Me." Also, in another episode, "All Systems No Go," he refers to himself as "George from London," and in "Dinner Guest," when Lizzie explains how her dad's been to London and Paris, George remarks, "I've been to London and Paris...
Growing up as the oldest child in a household in Toronto with only her mother and sister had suited her well and brought her up as a self-sufficient and independent young woman.
With the addition of a stepfather, two stepbrothers, a stepsister, new school, new house and overall a whole new life, Casey struggles to find her place within the new family.
So, when ultra-organized 15-year old Casey (Ashley Leggat) and her younger sister Lizzie (Jordan Todosey) move in with selfish and demanding Derek (Michael Seater), his younger brother Edwin (Daniel Magder), and their tantrum prone youngest sister Marti (Ariel Waller), space, privacy, and dealing with change quickly become serious challenges.