Judy Abbott is the protagonist of the anime, a cheerful and intelligent orphan girl with a distinctive appearance that includes red hair styled in braids sticking out to the sides, reminiscent of Pippi Longstocking. Her background is rooted in hardship, as she was abandoned as an infant on Bayson Avenue in New York City and subsequently taken in by the John Grier Home orphanage. It was within the strict and often difficult environment of the orphanage that she developed her notable talent for writing. Her life changes forever when an essay she writes catches the attention of a wealthy orphanage trustee using the pseudonym John Smith. He offers her a scholarship to attend the prestigious Lincoln Memorial High School, a condition being that she must write him a letter every month about her progress and daily life, with no expectation of a reply. Having only once glimpsed his elongated shadow, she affectionately nicknames him Daddy Long Legs and comes to view him as the only family she has.

In terms of personality, Judy is a natural storyteller who is very talkative and loves to share tales, bringing a whimsical and sincere energy to her interactions. Her roommates at school, the kind and supportive Sallie McBride and the initially snobbish Julia Pendleton, both come to enjoy her lively and free-spirited nature. Despite her outward cheerfulness, Judy carries a considerable inferiority complex rooted in her past as an orphan. She struggles deeply with shame about her background and is tormented by the secret, unable to confide in her friends for fear of how they might judge her. This inner conflict is a central part of her character, as she feels like a liar for not being open about where she came from.

Judy's primary motivation is to succeed in her studies and become an independent writer, driven by a desire to justify the faith her mysterious benefactor has placed in her. Throughout the story, which covers her three years of high school, she navigates the challenges of adapting to a new world of etiquette and high society. A key relationship in her life is with Jervis Pendleton, Julia's kind and unconventional uncle who finds high-society life mundane. Judy falls in love with him but is hesitant to confess her feelings, as her sense of inferiority makes her feel unworthy due to her orphan status.

Her role in the story is that of a classic coming-of-age protagonist. Over the course of the series, she matures considerably, learning important lessons from her teachers, her friends, and even from the silent presence of Daddy Long Legs. A significant part of her development involves a growing desire for independence, which leads her to argue with her benefactor and take on jobs against his wishes as she seeks to stand on her own. She perseveres through academic challenges, particularly in subjects like mathematics, while excelling in writing. Ultimately, her journey leads her to a powerful moment of self-acceptance when she publicly reveals her orphan background at her graduation ceremony, overcoming the shame that had plagued her for so long. Her notable abilities include her vivid imagination and skill as a writer, which is the very talent that earned her a chance at a new life and remains her path toward a future career.