The series opens with Yoo Na-bi enduring the humiliation of seeing her private vulnerabilities turned into an explicit artwork by her older boyfriend, prompting a clean break. That same night, she meets Park Jae-eon in a bar; an instant sensual attraction sparks, culminating in him drawing a butterfly on her arm. When she begins her new semester, she discovers Jae-eon is her junior classmate in the sculpture department.
They quickly fall into an ambiguous, sexually charged "situationship". While Jae-eon behaves like a devoted lover behind closed doors, he maintains a detached, uncommitted public persona, leaving Na-bi plagued by insecurity and rumors regarding his ex-girlfriend, Yoon Seol-ah. After a confrontation where Na-bi demands clarity and realizes Jae-eon cannot offer exclusivity, she breaks off the physical arrangement.
Seeking space, Na-bi retreats to her hometown of Sokcho. There, she reunites with Yang Do-hyeok, a warm childhood friend who openly confesses his feelings for her. However, the rest of the university sculpture department arrives for a retreat, bringing Jae-eon directly back into her orbit. Tensions boil over when Jae-eon attempts to win her back, leading to a physical and verbal clash with Do-hyeok.
Back in Seoul, a violent confrontation between Na-bi and Jae-eon in the pouring rain leaves both emotionally battered, with Na-bi formally telling him never to appear before her again. Shortly afterward, a freak studio accident completely shatters Na-bi's graduation sculpture just days before the senior exhibition. Jae-eon returns, offering his hands and technical skill strictly to help restore her vision, promising to leave her life for good once the piece is finished.
Together, they reconstruct the piece into an even more striking artwork of a winged figure. True to his word, Jae-eon disappears before the opening night. At the exhibition gallery, Na-bi reflects on her completed artwork, realizing that her feelings for Jae-eon were not merely passive manipulation, but a conscious passion she chooses to own. Spotting Jae-eon in the gallery crowd, she pursues him and initiates a confession. The series concludes with them deciding to date officially, with Na-bi candidly acknowledging: “I know it will bring me pain again, but nevertheless...”