Olivia tries to adapt to her new city, so she volunteers at the Heartlake City World Petacular, where she meets four other girls, and a friendship full of adventures and fun experiences develops between them.
The five friends continue their adventures in Heartlake City; they search for Olivia's aunt's fiancé in the forest, meet the girl Kate during a science camp on an island, and support Andrea's family in managing their new hotel.
In season 3, the five friends go on daily adventures from racing against time in an amusement park, to rescuing pets, while supporting each other in their personal crises.
In season 4, the five friends go on exciting adventures in Heartlake City: Emma becomes an investigator for the school paper, Mia suffers a skiing accident, Olivia is frustrated after her robot is sabotaged, Stephanie seeks to defeat her father in tennis, and they are united by a mysterious message...Read more that leads to a new discovery.