A young boy comes of age amidst increasing political unrest in 1973 Chile. No, it's not Machuca, but a boy named Gonzalo Infante (Matias Quer). Gonzalo is a member of the privileged Chilean upper class. His parents send him to St. Patrick's Catholic School, and they live a relatively luxurious life free of want. Partially because his mother (Aline Kuppenheim, Dreaming of Julia, Historias de Sexo) sleeps with a rich older man for food. Outside their home, things are changing. Communists rally daily on the streets while government supporters stage counter rallies. Gonzalo is pretty smart at school. He's a bit round, and not very popular. But he is still higher on the school pecking order than the new students.

Father McEnroe (Ernesto Malbran, Sub Terra) has allowed some local students to enroll in the school. Unlike the upper crust of Chile, these kids are local and poor. They cannot afford the school uniforms. The other kids ridicule them, and the parents are outraged; it smacks of Communism. One of the kids, Pedro Machuca (Ariel Mataluna) finds himself the brunt of the school bully. Gonzalo and Machuca are initially cool to each other, but once Gonzalo stands up for Pedro, the two become fast friends.

Pedro takes Gonzalo home with him, and the contrast is shocking. Gonzalo is used to a large house, and Pedro lives in a shack. He and his family support the Communists, but make money at rallies by selling flags to both sides (not very Communist, eh?). Gonzalo develops a crush on Pedro's cousin Silvana (Manuela Martelli, B-Happy), who has a passion he's never seen before. She firmly believes in her opinions, and mercilessly teases Gonzalo about his upbringing. When Pedro visits Gonzalo, the same sense of shock is not there. He simply accepts the fact that Gonzalo is well off.

As a film, Machuca is pretty slight. Director Andres Wood (Loco Fever, Revenge) co-wrote the story with Eliseo Altunaga (Hurricanes), Roberto Brodsky, and Mamoun Hassan. The relationship that Gonzalo has with Pedro and Silvana mimics the larger events of the impending revolution. As events reach a fever pitch in the streets, Gonzalo finds his friendship strained. Once the revolution occurs, he finds his life and his friendship profoundly different. It's not very deep, and the characters are a bit too dull to care about.