Lee Yeon-jae is a low-level office worker who has spent her entire life enduring mistreatment and self-sacrifice for the sake of her employer and others. After receiving a devastating diagnosis that she has only six months left to live, she decides to quit her job, empty her savings, and finally live life on her own terms. She embarks on a luxury trip to Okinawa, Japan, where she crosses paths with Kang Ji-wook, a wealthy and cynical director of a travel company who has grown apathetic toward life. As Yeon-jae compiles a bucket list of things she wants to do before she dies—including learning the tango and pursuing love—she inadvertently enters Ji-wook's life and slowly transforms his bleak outlook. However, keeping her terminal illness a secret becomes increasingly difficult as their bond deepens. The series explores themes of mortality, finding one's true passions, and the courage to love fearlessly in the face of an inevitable end.