Every summer for 11 years the Belyaevs' from Severodvinsk has been spending their vacation in Gelendzhik. The Northerners stay with their old friends in the same guesthouse. The long-term friendship of the families led to the fact that a young man, the son of the head of the "Northerners" family named Sasha, this summer, firmly decided to propose to Lyusya, the daughter of the head of the "Southerners" family ... Meanwhile, the Northerners' family is on the verge of divorce. Larisa is tired of tolerating her childish husband Seva Belyaev, who just can't grow up. The last straw was the news that Seva, before leaving on vacation, quit his job without telling anyone. The conflict within the family explodes, and Larisa announces to her husband that she intends to get a divorce ... The situation in the Southerners family is not easy either. It turns out that over this year Lyusya's father has found a new girlfriend - Madina.

The story is about a father who, after learning about his wife's infidelity, decides to take his twelve-year-old son and raise him on his own. In order to increase his chances of leaving a child in a divorce, he embarks on the path of becoming a demonstrative father – he joins the parent committee of the class. There he meets his former classmate, Sveta Surkova, who has changed a lot in twenty years. She turned from a gray nerd into a purposeful and self-confident woman who harshly directs moms from the parent committee, and even the school principal is afraid of her. Only one thing remained unchanged – her dislike for Shmelev, who did not give her a quiet life as a child. To stay on the parent committee, he must find a common language with Surkova and the rest of the moms.