Two children, Ignacio and Enrique, know love, the movies and fear in a religious school at the beginning of the 1960s. Father Manolo, director of the school and its professor of literature, is witness to and part of these discoveries. The three are followed through the next few decades, their reunion marking life and death.
A scorned ex-convict forces himself into the lives of the couple who put him behind bars.
Pepa resolves to kill herself with a batch of sleeping-pill-laced gazpacho after her lover leaves her. Fortunately, she is interrupted by a deliciously chaotic series of events.
Raimunda (Penélope Cruz) lives and works in Madrid with her husband Paco and their daughter, Paula. Raimunda's sister, Sole (Lola Dueñas), lives nearby. The two sisters miss their mother, Irene (Carmen Maura), who died several years ago in a house fire along with their father. When a former neighbor from their hometown reports that she has seen the ghost of Irene, the daughters do not believe her. After a murder and a family tragedy, however, Irene's spirit materializes around her daughters to comfort them.
In the 1970s, a foundling lad, Patrick "Kitten" Braden, comes of age by leaving his Irish town for London, in part to look for his mother and in part because his transgender nature is beyond the town's understanding.
Bob Hughes is the leader of a "family" of drug addicts consisting of his wife, Dianne, and another couple who feed their habit by robbing drug stores as they travel across the country.
Located in Madrid's Plaza del Sol, Km. 0 is the point from which all distances in Spain are measured from the capital. In Km. 0, it is also the meeting point for a gallery of characters. Bored, affluent housewife Marga meets up with gigolo Miguel, who co-habitates with gay Benjamin. Sergio, a soon-to-be-married office clerk who can't wait to lose his virginity, makes the acquaintance of prostitute Tatiana, while gay dancer Bruno meets Maximo. Meanwhile, wannabe director Pedro arranges to meet up with Silvia, an actress who wants to work in musicals directed by Gerardo, and bartender Mario is caught between Amor, who wants to marry him, and her little sister Roma, who is truly in love with him.
Originally entitled Threes, its plot revolves around Bobby (a single man unable to commit fully to a steady relationship, let alone marriage), the five married couples who are his best friends, and his three girlfriends. Unlike most book musicals, which follow a clearly delineated plot, this movie is a concept musical composed of short vignettes, presented in no particular chronological order, linked by a celebration for Bobby's 35th birthday.