Moteshiro High School was once an all-girls school, but that changed when a boy enrolled. As the only male student, Hodaka Saotome enters the school to pursue a career in fashion, notably as he prepares to inherit his family's tailoring business. However, most of his schoolmates are unwelcoming, leading to him being targeted and harassed.

One day, Saotome's seemingly kind classmate Kasumi Takae invites him to the rooftop for lunch. Believing this may be his chance to finally make a friend, he instead falls into her trap, where she attempts to blackmail him. To everyone's surprise, the dire situation is interrupted when Hanako Kuzuryuu, an intimidating delinquent, steps in to save Saotome.

After defending Saotome from Takae's plan, Hanako forms an unexpected friendship with him and tries her best to keep the boy safe from any mischief. With Hanako’s help, Saotome strives to avoid the other girls' antics and survive at the school.