Violet Paz, the charismatic narrator of this funny first novel, doesn't know much about her Cuban heritage when her grandmother offers to throw her a quinceañero, a traditional coming-of-age party for a 15-year-old girl. By party time, however, Violet has learned not only about Cuban culture but even "what is true" about her family and herself. Osa spins a host of story lines: Violet joins the speech team, performing an ever-evolving comedy routine about "the Loco Family" (she bases her material on a multi-day domino party that the police broke up); she fights with her father, who refuses to talk about Cuba (his parents fled to America with him when he was a baby); and she even finds her first boyfriend. The author can't quite flesh out all these characters and plot points to their full potential (the intimidating speech coach, for instance, seems exaggerated for no reason). Mostly, though, Violet and her wacky family and friends—including a pun-loving mother and a vegetarian who breaks up with her boyfriend when he wears leather to a PETA meeting—keep the fiesta moving at a lively clip. As a bonus, readers get some exposure to Cuban history and culture, including a smattering of Spanish words and phrases. Ages 12-up. (June)