This is a movie that actually made me laugh out loud, frequently - and that's a rare thing. The subject matter is often dark, or simply sad, but the banter is hilarious, the superficially depressing subject matter providing background for fun, zany, harshly satirical dialogue. There is also a warm and optimistic personal growth story that emerges from the cast of bitter or dysfunctional characters and their storyline - particularly the central character, Maria.
Maria, believably played by Mariana Mazza, is a complete failure, an unemployed woman of 30 who lives with her terminally ill mother, and has no ambitions beyond a vague hope of becoming an actress - her comically awful audition for a TV commercial demonstrating her lack of talent in that area. Things begin to change when she applies to work as a substitute teacher, and is assigned to a class, where her sharp, vulgar, outspoken manner appeals to the students, and Maria gradually begins to find herself and recognize her own potential.
This is a largely dialogue-driven film. The amusingly scathing remarks by the overworked principal about her high school students, interactions among the students themselves, and Maria's talks with friends, are consistently caustic and funny. The family interactions are warm, but also brutally honest and full of sharp quips and dark humour. This is particularly true of Maria's relationship with her mother: their charming ability to speak freely and without boundaries is both funny and a little shocking, particularly when talking about the mother's imminent death. The family's grief following her death is strikingly genuine.
The film follows Maria's slow and awkward development into a more confident and capable person, through a series of mishaps and errors in judgment, ranging from stupid to borderline illegal. The high school students' problems, and Maria's efforts to help, are presented in a decidedly unsentimental way, and success is never guaranteed, making the story's positive aspects more realistic than usual. It is a genuinely enjoyable underdog success story, which stands out for its distinctly harsh, funny script.