Two houses are separated by a wall (portrayed by a mute actor) in an unspecified American town (Overture).
The mysterious El Gallo tells about love and September (Try to Remember). He then begins to explain the plot of the play. Two young people, Matt and Luisa, live next door to each other and fall in love. However, their fathers are feuding and order them not to speak to each other. Luisa fantasizes about the experiences she wants to have in her life (Much More). Matt then delivers a speech about his love for Luisa, singing over the wall to her in a mock literary/heroic way (Metaphor). Matt and Luisa sneak up to the top of the wall and speak secretly of Luisa's romantic vision of Matt saving her from kidnapping. Matt's father, Mr. Hucklebee, then appears and tells about his philosophy of life and gardening (don't overwater). He calls Matt and orders him to come inside the house. Luisa's father, Mr. Bellomy, then enters and gives a contrasting philosophy of life and gardening (plenty of water). He then orders Luisa inside. He then calls to Hucklebee, and the two old friends boast about pretending to feud as a means to ensure that their children fall in love. They note that to manipulate children you need merely say "no" (Never Say No). Hucklebee tells Bellomy of his plan to end the feud by having Luisa "kidnapped" by a professional so that Matt can "rescue" her and appear heroic.
The hired professional, El Gallo (who is also the narrator), appears and offers the fathers a menu of different varieties of "rape" – in the literary sense of an abduction or kidnapping – that he can simulate (It Depends on What You Pay). Deciding to spare no expense for their beloved children (within reason), the fathers agree to a "first class" rape. A disheveled old actor with a failing memory, Henry, and his sidekick, Mortimer, who is dressed as an American Indian, arrive. El Gallo engages them to help with the staged kidnapping. Matt and Luisa return and speak of their love and hint at physical intimacy (Soon It's Gonna Rain). El Gallo and the actors burst in and carry out the moonlit abduction scenario; Matt "defeats" the three (Rape Ballet). The feud is ended, with the children and the fathers joined in a picturesque final tableau (Happy Ending). El Gallo collects the stage properties used in the "rape" and wonders aloud how long the lovers and their fathers will be able to maintain their elaborately joyful poses. He and the Mute leave.
The children and fathers are discovered in the same poses but are visibly shaky and exhausted from the effort. El Gallo observes that what seemed romantic by moonlight may lose its charm when exposed to the harsh light of day. He exchanges the moon for the blazing sun. The fathers and lovers begin to complain about one another, noticing all the flaws that have become glaringly visible by daylight (This Plum is too Ripe). The children try to recreate their romantic mood from the previous night and mock their fathers. Finally, in a fit of pique, Hucklebee reveals that their kidnapping and the feud were fake. Matt and Luisa are mortified, and the fathers' mutual recrimination quickly escalates into a real feud; they storm off to their respective houses. Matt sees El Gallo and, in a desperate attempt to regain his honor and Luisa's love, challenges him to a duel. El Gallo easily disarms Matt leaves him embarrassed. Matt and Luisa then argue fiercely; she calls him a poseur, while he calls her childish.
Matt is eager to leave the provincial town. He and El Gallo discuss his vision (I Can See It). Henry and Mortimer then appear and lead Matt off into the real world. A month passes, and the fathers have rebuilt the wall. They speak sadly of their children; Luisa is like a statue and does nothing but sit around; Matt still hasn't returned. They then sing about the uncertainties of raising children, as compared with the reliability of vegetable gardening (Plant a Radish). Luisa sees El Gallo watching her and is intrigued by the handsome, experienced bandit. Impulsively, she asks him to take her away to see the world. In a long fantasy sequence, they preview a series of romantic adventures through a mask of unreality, while in the background Matt is being abused and beaten by Henry and Mortimer portraying a series of unpleasant employers. Even Luisa's fantasies become increasingly exhausting and darkly underscored (Round and Round).
El Gallo tells Luisa to pack her things for the journey, but before she goes inside to do so, he asks her to give him her treasured necklace, a relic of her dead mother, as a pledge that she will return. As she goes inside, El Gallo promises her a world of beauty and grandeur; at the same time, Matt approaches to give a contrasting version of the cruel experiences that one can suffer "I Can See It" (reprise). As Luisa disappears, El Gallo turns to leave; Matt makes a pitiful attempt to stop him from hurting Luisa, but El Gallo knocks him away and disappears. Luisa returns to find that El Gallo has left her, and sits in tears. El Gallo, as the narrator, tells poetically that he had to hurt Matt and Luisa, and how he hurt himself in the process. Matt comforts Luisa, and he tells her a little about his experiences, and the two realize that everything they wanted was each other (They Were You; Metaphor (reprise)), but that they now understand that more deeply. The Fathers then return joyfully and are about to tear down the wall, when El Gallo reminds them that the wall must always remain (Try to Remember (reprise)).