Mina and her father John have always been dependent on each other, until her father met his new happiness in life - Helen! John and Helen are about to get married, and Mina also has a new sister Jenny. From then on, her world became a mess. Jenny is a very mean girl who always wants to drive Mina's guinea pig friend away. Mina is frustrated and doesn't want to live with her new sister. One night, Mina accidentally broke into her dream...