A third-year student at a prestigious college preparatory high school, Yukari Hayasaka is exhausted by the pressure to study for entrance exams and the mundane expectations set by her strict mother. Her routine life takes an unexpected turn when she is scouted on the street by Arashi Nagase, a punk-styled student at the Yazawa School of Arts. Initially frightened by his appearance, Yukari is soon introduced to the rest of his fashion collective: the childlike and sweet Miwako, the tall and elegant Isabella, and their charismatic yet enigmatic leader, Jouji Koizumi, who goes by George. The group, operating under the label Paradise Kiss, is searching for a model to showcase their designs at an upcoming school fashion show, and they have chosen Yukari as their muse.

Despite her initial condescending attitude towards their unconventional lives, Yukari becomes drawn to their passion and freedom. She agrees to model for them, and as she spends more time in their atelier helping sew beads onto the dress, she falls into an intense and whirlwind romance with George. However, their relationship is turbulent, as George is alternately warm and cold, manipulative and inspiring, always pushing Yukari to become an independent woman who makes her own choices. Inspired by the group's dedication to their dreams, Yukari decides to forge her own path, leading to a major confrontation with her mother. She runs away from home and drops out of school to pursue a career in modeling.

As the deadline for the fashion show approaches, the members of Paradise Kiss face their own struggles. Arashi battles jealousy over Miwako’s friendship with her childhood companion (and Yukari’s classmate), the studious Hiroyuki Tokumori. Isabella, a transgender woman, acts as a supportive mother figure to the group. Despite their hard work, the Paradise Kiss label fails to find commercial success, and the group agrees to disband following the show. On the day of the competition, Yukari walks the runway in their completed dress. Although she mesmerizes the audience, the team only wins second place. Following their graduation, George decides to pursue his dream of studying fashion design in Paris, and he invites Yukari to join him. Recognizing that her own career is just beginning and that their lifestyles are ultimately incompatible, Yukari declines.

In the live-action adaptation, the story diverges from the original manga. Years after their separation, Yukari has become a successful international model. While on a modeling job in New York City, she discovers evidence that George has been secretly following her career, having kept every magazine she has appeared in. Tracking him down to his studio, the two share a reunion and a kiss, suggesting that their paths have crossed once more.