In this story, Big Head Son, Small Head Dad, and Apron Mom form a working-class family, while Small Head Dad's cousin Dayu and his son Xiaoyu come from a relatively wealthy household. Both families have their own minor troubles, so Big Head Son and Xiaoyu begin to envy each other's fathers. At an amusement park wishing machine, they make a wish together, hoping for a new dad like the other's in the coming year. Surprisingly, the wishing machine grants their wish, and thus they begin their swapped lives...