13-year-old Senja moves to a new town with her poor single mother. On the first day of school, Senja meets wealthy Iina and lies about being rich herself.
Senja doesn't dare tell Iina the truth and lies more. Nosy neighbor Olga also tries to snoop on Senja's life. Iina, on the other hand, is excited about her new friend.
Senja tries to make friends with Iina's friends Miisa and Jenna, but they treat the new girl with hostility. Senja gets new ideas for her lies from the eco-minded neighbor boy, Samuel.
At school, there is a discussion about young people's trips abroad and Senja is embarrassed that she hasn't been anywhere. Senja goes to visit Iina and the girls go shopping together, where Senja runs into Samuel again.
Senja finds out something terrible and has a hard time getting her thoughts together. And Senja can't even afford to go on a class trip. Miisa starts to doubt Senja's stories and the girls follow her home.
Iina and her father discuss their friendship with Senja. The girls end up playing frisbee golf together. Senja's mother says she got a job in Norway and Senja should now temporarily move to a brand new home.
Senja adjusts to life in her new home with varying success. It's also difficult with Iina, the young people's relationship is completely broken and Miisa tries to reveal the truth about Senja.
Senja lies to her classmates again and pretends that her new home is her real home. Iina's parents argue and she goes to Senja's to vent her feelings.
The girls go on a class trip to a climbing center and it is almost revealed that Senja knows Samuel. Miisa's suspicions towards Senja grow.
Senja is suddenly exposed to big things that she finds difficult to accept. Miisa tries to turn Iina against Senja.
Senja's lies begin to be revealed one by one and Miisa in particular gets more water for her mill. Senja opens up about her troubles to Samuel.
The girls suspect Senja of being a thief and she begins to be discriminated against at school. However, Senja is most worried about what will happen to her mother, who is in a difficult situation.
Senja has to sort things out with everyone. In the end, it all depends on whether anyone can trust Senja anymore.