Sarah's life changes overnight when her father decides to marry Mary. Her, that loved to be an only girl, finds herself forced to move in with her. Nothing very abnormal but it was without counting on her "step-brothers": Tom, who is 8 years old and always have crazy ideas and Brian, who is 16 years old, like her and who is simply arrogant. They hate each other especially since Brian became popular and not Sarah ... In addition to having to manage her family which has become atrocious, she must manage the high school and the return of Marc, the guy she has always been crazy about.