"Peach!" is a manga series that centers on Momo Adachi, a high school student who becomes entangled in a series of romantic and comedic situations after transferring to an all-boys school. Momo, who has a feminine appearance, is often mistaken for a girl, leading to misunderstandings and humorous encounters. The story explores themes of identity, friendship, and romance as Momo navigates the challenges of fitting into a new environment while maintaining his true self.

The narrative begins with Momo's decision to attend an all-boys school to escape the constant teasing he faced at his previous co-ed school due to his looks. However, his plan backfires when his classmates and even some teachers mistake him for a girl. This confusion sets off a chain of events that involve various characters, including Soshi Okita, a popular and confident classmate who becomes one of Momo's closest friends. Soshi often finds himself in awkward situations due to his growing feelings for Momo, further complicating their relationship.

Other key characters include Kairi Shirogane, a stoic and serious student who initially views Momo with suspicion but gradually warms up to him, and Aoi Koga, a cheerful and outgoing classmate who adds to the comedic dynamics of the group. The interactions between these characters drive much of the plot, with each character contributing to the series' blend of humor, drama, and romance.

As the story progresses, Momo's relationships with his classmates deepen, and he begins to confront his own feelings and insecurities. The series balances lighthearted moments with more serious themes, such as self-acceptance and the complexities of human relationships. Through its engaging narrative and well-developed characters, "Peach!" offers a compelling exploration of adolescence and the challenges of navigating identity and emotions in a unique setting.