Season 1
Professor Lucia Liguori, divorced and living in Milan, during a trip to Rome, accidentally meets Giulio Cesaroni, her boyfriend when they were kids and a widower for a few years. The passion between the two is rekindled and the decision to get married is almost immediate. Lucia moves to Rome in Giulio's single-family house together with her daughters from her first marriage, Eva and Alice. Thus begins the story of the Cesaronis, an extended family made up of seven members: the two parents, her two daughters and his three sons, Marco and Rudi (the same age as Eva and Alice respectively), and little Mimmo. There are also some other characters who interact assiduously with the inhabitants of the Cesaroni house: Gabriella Lanfranchi, Lucia's mother and a long-time resident of the "Garbatella" neighborhood; Cesare, Giulio's brother and his partner in the "Garbatella" wine shop; Ezio Masetti, an old friend of Giulio and Cesare and a regular customer of the wine shop; Stefania, Ezio's wife and Lucia's schoolmate; and finally Walter, Ezio and Stefania's son and Marco's best friend. Giulio and Lucia's marriage is put to the test several times, mainly by the terrible relationship created between their respective children. A further obstacle is Sergio Cudicini, Lucia's ex-husband, who interferes so that the woman and her daughters return to him, first by unsuccessfully threatening Giulio and his wife, then by staging a fake illness. The charade is discovered and the couple can finally get married.
Marco is in love with Eva from the start, but she already has a boyfriend who lives in Milan. The point of contact between the two stepbrothers is music, a sector in which Marco dreams of making a name for himself. Marco tries several times to declare his love to Eva but, failing, decides to confide in his father privately. Giulio is firmly against a possible relationship between the two, considering it morally inappropriate and potentially harmful to the family balance: he gets angry with his son, and urges him to date other people. The young man can't stop desiring Eva until he meets Rachele, a new teacher of his with whom he begins a love affair. Eva, after having considered Marco only as a good friend and brother for a long time, realizes that she is in love with him. Following the end of the relationship between Marco and Rachele, Eva would like to conquer Marco, but the only result is the moralistic sermons of Giulio who is adamant in wanting to keep the two young people apart.
Cesare meets Pamela, a prostitute hired to make friends and family believe that he is engaged. From this act, genuine feelings are born on the part of both, so much so that they go on vacation together. Rudi and Alice, during the time span of this season, constantly argue and declare their mutual disdain, but on rare occasions they behave like brothers.
Summer vacation time arrives and Giulio sends Marco and Eva to two different places. Through a series of coincidences, the two find themselves on the same ferry, ready to leave together. Giulio, as soon as he finds out, tells Lucia about the mutual love that has developed between their respective children. In agreement with his wife, who shares his moralistic positions, Giulio makes an anonymous phone call to the port authority in which he says that a bomb has been placed on the ferry.
Season 2
Marco and Eva meet on the last day of vacation in the same hotel. The two have spent the summer apart, not because of Giulio's anonymous phone call, but because of Rachele's reappearance and an apparent reconciliation between the teacher and the student. However, Marco decides once and for all to leave Rachele and declares his love for Eva, who reciprocates. Their relationship is kept hidden from the family members, for fear of Giulio and Lucia's moralism. However, the kids are discovered when their respective parents find them naked and embracing in their bed. Giulio suffers a heart attack. Marco runs away from home and takes refuge in London. Eva joins Marco in England, but learns that her stepbrother went there on his own initiative, and not because his family forced him to. Feeling betrayed and abandoned, the young woman returns home alone and is determined to turn the page once and for all. The girl becomes infatuated with Alex, an emerging chef. Then Marco returns to Rome, belatedly convinced not to let himself be influenced by his family's moralism. Eva, after a furious reaction against her revived stepbrother, feels confused and is undecided between the two men she loves. Eva chooses the young Cesaroni and breaks up with Alex, but the situation turns upside down, and it is Marco who verbally attacks her, feeling betrayed. Days of clashes and teasing between the stepbrothers follow, but just when Marco wants to declare his love for Eva, she resumes her relationship with Alex. Marco realizes he made a mistake and accepts the story between Alex and his stepsister.
Alice and Rudi are in eighth grade. The young girl develops a crush on Umberto at the beginning of the season, but Rudi's pranks put her in a bad light. Alice's feelings are not reciprocated, since Umberto exploits her to see his sister Eva or asks her to babysit his little brother when he goes out with other girls.
The Barilon's have moved from Padua, becoming the Cesaroni's neighbors. Antonio Barilon, the head of the family, runs a bathroom fixtures shop near the liquor store, and initially does not win the sympathy of Giulio and Cesare, but the relationship is always quite cordial. His wife Germana, on the other hand, is a real antagonist and often acts inappropriately towards the neighbors. Lorenzo, Antonio and Germana's son, initially torments Rudi but then becomes his friend. Pamela asks Cesare to explain his running away during the holidays. He replies that he no longer loves her but secretly confesses to his friends that he was actually ashamed to tell her that he was a virgin.
A girl named Carlotta, who is repeating a year, arrives at school and immediately becomes a great friend of Eva. Walter and Carlotta begin a relationship.
The final exams are approaching and the boys must think about their future. Marco tries to make it in music and Eva wants to move with Alex to New York to attend Columbia University. The two pass the exams, just like Walter and Carlotta. During the end-of-year celebrations, Marco finds the acceptance letter to the Academy he had applied to hanging on the door of his room. Eva opens the envelope and reveals that Marco has been accepted. Transported by happiness, the two kiss and make love. Once downstairs, Marco overhears a conversation between Eva and Alex and understands that now it is up to her to choose between the two.
