While there are a few different characters in the book, the story is told entirely from the perspective of the protagonist, "J" (whose full name is never revealed). This means the reader experiences the story through her eyes and learns her thoughts, feelings, and understanding of the events happening around her.
It's first-person narration, meaning the narrator uses "I" and "my" throughout the story. This allows for an intimate and personal look into J's coming-of-age experiences, her insecurities, her hopes, and her struggles with navigating adolescence.
Let me know if you'd like to discuss any other aspects of "Fifteen" or Beverly Cleary's work!