In Alfonso Cuaron's controversial road movie drama Y Tu Mama Tambien, it mimics a classic three act structure. While there is some plot and action driving the story, it's the characters and their deeply rooted backstories really moving the narrative along. Specifically, one of the primary structural elements of Cuaron's film that makes it unlike any other is the lengthy narration that occurs while the scenes are happening. Rather than having the audience guess as to where these characters come from and what their personalities reveal about them, he just flat out tells us in the narration; from their college degrees to what their parents do for a living. And since the movie lacks quick cuts and is shown almost entirely in long takes, it makes us focus more on what the characters and the narrator are saying, rather than what's going on around them. This is effective because what the main characters, Tenoch and Julio (having just graduated high school), say and do to one another reveals a great deal about the relationship they have with each other.
The film does follow a chronological story. The inciting incident of Act One immediately lets us know what's in store for us: Julio, Tenoch, and their love interest (Tenoch's cousin through marriage), will embark on a road trip that's bound to change their lives in some way. Cuaron gives special attention to the setup in Act One of the film because it distinguishes rather clearly who these people are. Tenoch comes from a wealthy family, whereas Julio does not. Their friendship is rooted on competition in every way, but they still care for each other. This rings especially true in the scene in which they are racing in the pool. Julio falls behind and for a few seconds, Tenoch stops what he's doing to look back at him and make sure he's okay. It's these small, minute details that reveal character.
Another way Cuaron manipulates the structure is with the character of Luisa. After the party where she meets Tenoch and Julio, we first see her waiting nervously in the doctor's office. We then see her crying in bed. And after her fiance calls and tells her he cheated on her, she breaks down. Thus, her decision to immediately call Tenoch the very next day and ask to join him and Julio on their trip to the fictional place Heaven's Mouth, shows that she needs to get away from whatever's worrying her. And for those who know the ending of the film would say that embarking on this journey ends up being the best decision she's ever made in her life.
The structure of this road movie works for a few reasons. For one, it's not an episodic road trip where a series of unfortunate events occur that stop Julio, Tenoch, and Luisa from getting to what they want. In fact, there wasn't much at stake for them. All they wanted was an experience, and their journey to "Heaven's Mouth" helped them find this experience, rather than hinder them. Also, we didn't have to see every road they turned down or every hotel they might have stayed at along the way. What was important was the interactions between the characters (i.e. Luisa sleeps with Tenoch and Julio gets jealous, Luisa says goodbye to her fiance for the last time over the phone, the group meets a family of fishermen that gives them insight about life). The structure seemed to flow naturally while still maintaining the initial story at hand. Without making it too obvious, Cuaron was able to successfully create an arc of change in each of the characters just by simply putting them in a car and having them drive endlessly, talking about anything and everything.