Kakashi orders Naruto, Sasuke, and Sakura to watch a movie before their next mission. Naruto is a big fan of the lead actress. After the movie, they see the heroine in person and being chased. They help her and Naruto asks for an autograph but she wouldn't give him one. When the three returns, Kakashi tells them about their mission: to escort the actress to the Snow Country to film a new movie.
Most Naruto Movies or any movies based on series are usually of a poor quality for the same reasons that fillers are, it's because they have no effect on the actual story it's worse then something happening and finding out it was all a dream. You never see any of those characters again and despite a longer running time than a standard episode lack the character and story depth of the series. It's easy to think you can write a better story but fitting a Mangaka's work into a fulfilling and captivating narrative is always a mammoth task even for professionals.