When they were still schoolgirls, Arina, Katya and Anya swore an oath that they would never betray each other and would always be together. As the years go by, the girls get older and form a musical group called 3D. At first, nothing works out for them, but one day they write a hit that makes them popular. The friends immediately find a producer, and now it seems that everything will only get better, but not everyone will cope with the test of fame and success.