Britney Spears plays "an innocent girl with a lot of aspirations" in her big-screen debut, according to one of her "What Are Friends For" co-stars.
The film, due out early next year, finds Spears' character, Lucy, on a cross-country adventure seeking musical fame, said Justin Long, who plays her best friend from high school.
"It's like a road trip buddy movie for girls," said Long, who appeared in "Galaxy Quest" but is best known as Warren Cheswick on the NBC comedy "Ed." "[Britney] plays a very wide-eyed girl. She's a great actress. People are going to be surprised."
So how is Lucy different from Britney?
"Britney's a lot more grounded than the character she plays," Long said. "She could not have been more down to earth. She's the sweetest girl. After 10 minutes, I forgot she was a big pop star."
"What Are Friends For," Spears' first acting gig since she hosted "Saturday Night Live" last year, features the former "Mickey Mouse Club" star alongside several seasoned actors.
Dan Aykroyd plays her father and Kim Cattrall ("Sex and the City") plays her mother, according to spokespeople for both actors. Spears' reps refused to comment on the movie.
Taryn Manning ("Crazy/Beautiful") and Zoe Saldana ("Center Stage") play Spears' friends who join her on the journey, Long said, while Anson Mount ("Urban Legends: Final Cut") takes on the role of a love interest she meets along the way.
"What Are Friends For" was directed by Tamra Davis ("Billy Madison"), the wife of Beastie Boy Mike D. It was filmed on a set in Los Angeles and on location near Spears' hometown of Kentwood, Louisiana (see "Britney Spears Begins Work On Film Debut").
"I really think it's going to be a good movie," Long said. "I know people are going to see it, but I think they are going to be surprised at how charming and genuine it is."
The 23-year-old Deerfield, Connecticut, native also stars in the upcoming horror flick "Jeepers Creepers," due August 24. "There hasn't been a good old-fashioned monster movie in a while," Long said. "I hope it invigorates the genre a little bit."