Timmy Turner is excited to gift his cousin Vivian with his Fairy Godparents on her first day living in Dimmsdale. However, when her new stepbrother Roy accidentally witnesses the transfer, Viv and Roy are forced to share Cosmo and Wanda.

Viv and Roy must resolve their differences and come together to rescue Cosmo and Wanda, and stop Mr. Crocker and Vicky's evil plan to control and take over the Fairy World.