Momo Adachi is the protagonist of the anime Peach Girl. She is a high school student who was formerly a member of the swim team, a background that has left her with a deep tan and bleached hair. Because of her appearance, her classmates mistakenly stereotype her as a promiscuous "easy girl" and spread cruel rumors about her sexual history. In reality, Momo is shy, insecure, and deeply caring. She is considerate toward others and tries to help people even when it goes against her own judgment, which often leads her to forgive too quickly. She also has a fierce temper that flares up when she is pushed too far.

Momo’s primary motivations are to be accepted for who she is and to find genuine love and friendship. She has loved Kazuya Toujigamori, known as Toji, since junior high school, but she never confessed because she believed he preferred girls with lighter skin. When a new student, Kairi Okayasu, develops a strong interest in her and publicly declares his love, Momo finds herself caught in a complicated love triangle. She initially finds Kairi annoying but eventually begins to date him and falls in love, especially after Toji breaks up with her under pressure from the scheming Sae.

Momo’s key relationships shape her journey. Her friendship with Sae Kashiwagi is a central source of conflict: Sae appears to be Momo’s only friend but is secretly the one spreading the rumors, driven by jealousy and her own desire for Toji. Sae’s manipulations repeatedly sabotage Momo’s happiness and force Momo to confront betrayal. Toji is Momo’s long-standing crush; their relationship is marked by misunderstandings and obstacles created by Sae. Kairi offers a contrasting relationship—he is straightforward, persistent, and eventually helps Momo grow more confident. Momo also relies on Misao, the school nurse, as a big-sister figure for guidance.

Throughout the story, Momo undergoes significant development. She starts as a self-conscious girl trying to change her appearance to fit in, but over time she learns to accept her natural looks and stand up for herself. She becomes more emotionally resilient, navigating not only romantic turmoil but also social bullying and betrayal. Her notable abilities include her athleticism from swimming, which gives her physical strength and endurance, and her emotional capacity to forgive and keep fighting for the people she cares about. Her role as the central character drives the series’ exploration of stereotypes, toxic friendships, and the search for authentic love and self‑worth.