"Every sexual act performed by the three participants must be reported in this notebook" states the first rule of the black notebook, in which three friends meticulously record their meetings and the unspeakable secrets of their lives.
Mavi is an interior designer, has a boring boyfriend, and collects smells of people in vacuum-sealed clothing. Through her we follow the events of the three friends and the use of the black notebook, which under the pretext of documenting and giving votes to sexual relations, hides instead thoughts, follies, confessions, secrets, perhaps even crimes ...
By means of those annotations reported on the diary-agenda, every single character brings the spectators into the exclusive private of their innermost desires. On this notebook are collected the most scabrous confidences, the most shocking details, the bastard reflections or even simply the moments of confusion and sadness.
The two friends who participate in the "game" of the black notebook as well as Mavi are Paola and Riccardo.
Paola is an aspiring starlet of rare beauty. Sports journalist of a local TV, goes to bed with anyone to make a career, stirred up by a mother-mantis. It's since her adolescence that the dear mother pushes her daughter not to set moral barriers of any kind in order to succeed.
Riccardo, an avid serial lover, is leading to the downfall of the fashionable club that he paid with his grandmother's money and who runs with great madness. It is what is said to be a spoiled father's son, who basks in the fortunate privileged situation.
Women are his irresistible fixation, collect a conquest after another, obsessively, "serial", beautiful and less beautiful hardly escape his network of inveterate seducer. But he has a dream, the only woman he has never had and he wants since he was a boy a little unlucky. When he finally has her, he will find out that dreams are better if they remain so.
The black notebook, started only as a game to share their sexual adventures, with lots of votes and rules, will end up showing secret and sometimes unexpected aspects of the three friends.
Between moments of sex, others of comedy and extreme situations, Mavi will let her frustrations emerge and her desire for redemption, Paola, just when she is about to satisfy her mother's ambition, will be blocked by an illness that she, accustomed to suffer , will transform into its own success. Riccardo, left penniless by his father, will bring out a very dangerous side of himself, criminal ...
But during the course of events we will see that in that black book there is something more than the stories told. Why does Mavi lose the thread of his story every now and then? What does that skyscraper have to do with it? Why do stories sometimes mix? Why do we feel the presence of someone else, someone who seems to have always spied on the lives of the three friends? What is the relationship between Mavi and his particular psychiatrist? What is the real secret of the black book?