The music director Shinsa-dong Tiger wanted to meet the actresses beforehand to analyze their vocal range, color, and more to create the perfect idol song for the movie. However, the crew did not want to put pressure on the actresses, so they convinced them that he was a new actor participating in the film, and conducted a casual meeting at a karaoke "no-rae-bang." There, the actresses were able to conduct their "auditions" comfortably.
Pure, the films' fictional K-Pop group's opponents in various scenes, is played by K-Pop girl group After School, who perform their own song "Bang" throughout the film.
White's protagonist, Eun-ju, is played by Ham Eun-jeong, who is a member of K-Pop girl group T-ARA.