"Peach Girl" centers on Momo Adachi, a high school student whose tanned skin and bleached hair lead to misconceptions about her personality. Despite her appearance, Momo is kind-hearted and reserved, harboring feelings for her classmate, Toji. However, her best friend, Sae Kashiwagi, spreads rumors that Momo is promiscuous, creating tension and misunderstandings among their peers. Sae, secretly in love with Toji, manipulates situations to sabotage Momo's chances with him.

Toji, a popular and athletic student, is initially oblivious to Momo's feelings and the rumors surrounding her. His indecisiveness and lack of awareness complicate their relationship. Meanwhile, Kairi Okayasu, a flirtatious and rebellious classmate, becomes infatuated with Momo and actively pursues her, adding further complexity to the love triangle. Kairi's persistence and charm create moments of conflict and confusion for Momo as she navigates her emotions.

The narrative explores themes of jealousy, betrayal, and self-discovery as Momo struggles to reconcile her true self with the image others project onto her. Sae's manipulative behavior escalates, leading to confrontations that test the bonds of friendship and trust. Momo's journey involves overcoming societal judgments, asserting her identity, and deciding where her heart truly lies.

Secondary characters, such as Momo's supportive friend Misao and Sae's loyal follower Nagashima, contribute to the dynamics of the story, highlighting the complexities of high school relationships. The series balances moments of humor, drama, and romance, capturing the emotional turbulence of adolescence.

Throughout the series, misunderstandings and miscommunications drive much of the conflict, but moments of clarity and growth allow the characters to evolve. Momo's resilience and determination to stay true to herself serve as the emotional core of the story, making "Peach Girl" a compelling exploration of love, friendship, and self-acceptance.