Home-movie images of snapshots and postcards accompanied by a voice-over that begins “I remember…” let us know that “crazy/beautiful” will be a sentimental film.

Trust your instincts; those first few moments are not misleading. They give way to a chance encounter on a beach: privileged white girl Nicole (Kirsten Dunst) is doing community service to atone for some unnamed sin, and Hispanic over-achiever Carlos (Jay Hernandez) strikes up a conversation with her.

As fate would have it, they both attend the same rich high school, though he does it only by riding the bus two hours each direction, working hard, and staying out of trouble. She takes her good life for granted, is the daughter of a congressman (Bruce Davison), and spends as much time as possible ditching school and drinking with her like-minded girlfriend Maddy (Taryn Manning).

A relationship begins. Nicole’s irresponsibility gets Carlos into trouble, helped a little by the fact that he’s of Mexican descent in Los Angeles, where Hispanics are often lumped in with the trouble-makers. Carlos, who wants to go to the naval academy, begins to neglect his studies, entranced by this bohemian waif.

Nicole’s troubles stem partly from having grown up without a mother, but also partly from what may be some kind of chemical imbalance. Her father, at the end of his rope, threatens to send her off to a school for troubled kids in Escalante, Utah (a fate worse than death, surely).

Kirsten Dunst (“The Virgin Suicides,” “Bring It on” and “Drop Dead Gorgeous”), one of our smartest young actresses, has chosen yet another role that allows her to do something different. While the Freddie Prinze Jr.’s and the Seann William Scotts of the world keep playing the same part over and over again, Dunst has consistently appeared only in films that are at least interesting, if not downright great.

This is a superb transitional role for her. She’s a high school student again, but one with a grown-up, tragic air about her. Dunst is utterly convincing as the frail, obnoxious Nicole — a dubious achievement, perhaps, given how little patience we have for people like that in real life, but an achievement nonetheless.

Jay Hernandez, meanwhile, is a revelation. In his first starring role, he commands as much attention as does his more experienced screen partner. He’s an intuitive, charismatic actor. He will go far.

“crazy/beautiful,” for as watchable as it is, doesn’t stir the emotions so much as it skips stones across them. There’s a splash of romance here, a splash of tragedy there, maybe a family drama over there. It is compelling at times, but rarely engrosses all the senses the way you’d expect a romantic drama to do. It’s a sincere movie, though, that doesn’t pander to its teen-age target audience. For that reason alone, it probably will not do well at the box office, but it should.

B (; PG-13, lots of profanity, some sexuality, a little violence.)