Alex Belli is a 37 year old advertising executive whose fiancée Elena has just left him, and who is having difficulty at work trying to think of a good advertising campaign for a new Japanese product. Niki is a bubbly 17 year old student. She has three best friends with whom she shares all her problems, and an annoying ex-boyfriend Fabio who is set on getting her back, but Niki's not interested. One day on his way to work, Alex collides with Niki on a city street. They soon begin a romance, despite their 20-year age gap.

Second part of the film "Sorry if I love you". Alex (Raoul Bova) and Niki (Michela Quattrociocche) are more in love than ever. They have just returned from the lighthouse on the island Blu where they have lived unforgettable days. Niki returns to see his friends, but a number of important changes in their lives will test the friendship of the girls. Alex also resume life with his old friends. All of them, Flavio, Enrico and Pietro, are no longer serene and safe husbands due to certain difficulties that have compromised their marriages.

Fabio is in love with his colleague Linda, but she has never even seen him until he's mistaken for her boyfriend. Paolo and Mario leave for a luxurious vacation in Rio de Janeiro for Christmas, without knowing that their sons have booked a trip for the same low-cost destination and, for a problem of homonymy between fathers and sons, the two holidays are exchanged.