Na Bo-ra, a cheerful and lively seventeen-year-old high school student, finds herself caught in a whirlwind of emotions and unexpected relationships in What's After the Movie set in 1999. Her close friend, Roh Yoon-seo, plays Yeon-du, who is preparing to leave Korea for the United States to undergo heart surgery. Before her departure, Yeon-du confides in Bo-ra about her crush on a boy from their school, whom she believes is named Baek Hyun-jin. Eager to help her friend, Bo-ra promises to find out everything she can about this boy and promises to stay in touch by emailing her updates. Feeling reassured, Yeon-du leaves for her medical trip, leaving Bo-ra alone with her own feelings and curiosity.
At school, Bo-ra begins to follow Hyun-jin, hoping to learn more about him. She learns that Hyun-jin and his best friend, Byeon Woo-seok, have joined the school’s broadcasting club, so she auditions and successfully becomes a member. Interestingly, Hyun-jin does not join the club, which prompts Bo-ra to spend more time with [Byeon Woo-seok], trying to get closer to Hyun-jin by observing him from afar.
Soon, Hyun-jin mistakenly believes that Bo-ra has romantic interest in him and asks her out on a date. However, she respectfully declines, revealing that her feelings are directed elsewhere. It is then that Bo-ra realizes her heart has fluttered for Woon-ho, her friend, who incidentally has also developed feelings for her. As their relationship begins to grow, Yeon-du returns from the US after successfully undergoing her surgery.
Soon, the truth emerges: Bo-ra had been chasing the wrong boy all along. The boy Yeon-du loved, the real Baek Hyun-jin, is actually none other than Woon-ho, who had been wearing a jacket bearing Hyun-jin’s name tag, leading to the confusion. Despite her feelings, Bo-ra chooses loyalty and friendship over romance and keeps her love hidden to protect Yeon-du, especially considering her health condition. Woon-ho, unaware of her feelings, is preparing to move back to New Zealand with his mother and younger brother, leaving Bo-ra heartbroken and unsure of how to hold on to her feelings.
On the day of Woon-ho’s departure, with emotional support from Yeon-du and Hyun-jin, Bo-ra rushes to the train station, trying to confess her love before it’s too late. They share tender moments, and Woon-ho, Woon-ho’s brother Joseph, and Hyun-jin make heartfelt confessions, affirming their affection. Despite her hopes, Woon-ho suddenly stops replying to Bo-ra’s emails after he leaves, and she is left in a storm of confusion and pain.
Years pass, and Bo-ra matures through her university years, carrying the memories of her youthful love. In 2019, she receives an invitation to an art exhibition from a mysterious sender named Joseph. When she attends, she learns that Joseph is Woon-ho’s younger brother and that Woon-ho tragically died in an accident years ago. Joseph thanks Bo-ra for remembering Woon-ho, sharing that Woon-ho’s happiest moments were spent with her, and presents her with a touching video created by Woon-ho himself, showcasing their cherished memories together.
The story concludes on a bittersweet note as Bo-ra, now a young woman, watches this heartfelt video, understanding that although her love story was cut short, Woon-ho’s memories and their connection remain a beautiful part of her life forever.
