The title character is a young Brazilian boy perhaps 11 or 12 years old. His father begins to notice that the introverted youngster is gravitating not toward girls but toward other, slightly older boys. He sees Xavier chatting amicably with a fellow student on the stairs at school and watches him follow another lad walking along the sidewalk with his gaze.
Both Xavier and his dad, Nicolas, are gifted musically: Nicolas plays the guitar, and his son is a drummer who is so wrapped up in his rhythms that he carries drumsticks around with him and drums on air as he walks or sits, tapping his foot.
In one scene, Nicolas is in the kitchen chopping vegetables as Xavier is drumming (this time on a real drum set) in an adjoining room. The boy stops for a few moments, but dad appreciates his son's musical talent so much that he encourages him to resume playing.
During an afternoon party at his uncle's home, Xavier is seated at a table with other kids somewhat older than himself. He listens and smiles at their stories and anecdotes, gazing frequently and longingly at the handsome Filipe, who expresses interest in learning to be a drummer. Xavier is delighted to give him a lesson, and the two boys drum on air, imagining they're performing at a concert. As Nicolas is chatting with his brother some distance away, he observes his son's attraction to Filipe. Then the older youngsters, including Filipe, leave to go to an entertainment venue where Xavier is too young to enter, so he remains behind. But Xavier's dad encourages Filipe to take the drumsticks with him, saying he can return them later, thereby confirming that he aware of his son's feelings and is on board with his behavior and identity.
Nicolas asks for a guitar and, ending his recent musical silence, sings to his son. The song is O Leãonzinho ("Little Lion"), and its lyrics speak of the singer's love and admiration for the little one who brings sunlight and joy into his life. At the conclusion of this simple but heartwarming performance, Xavier says simply, "I love you, dad."