Lili (Sára Varga-Járó), is after the tragic loss of her love, spends her days lonely as a cocoon, until she comes across her mother's diary and a stack of love letters in her parents' apartment. As she begins to read them, the past comes to life in front of her, one of the unforgettable summers of the early nineties: Lili's mother, Eszter (Franciska Töröcsik), is on vacation at Lake Balaton with her two friends. She is determined to remain loyal to her 'stiff upper lip' boyfriend at home, but her plans are thoroughly messed up when she meets Geri (Márk Ember), who is relaxed, funny and has another very good quality: as the frontman of a band, he performs on the beach in Szigliget with his friends (Peti Marics , Kirády Marcell). What can be of this? Confusion? Love? Jealousy? A few kisses? A few slaps? More kisses? This is the minimum. The summer on the shores of Lake Balaton changes the lives of young people, and even affects the lives of their children.