Just Between Lovers tells the poignant story of Lee Kang-doo and Ha Moon-soo, two individuals whose lives are irrevocably altered by a tragic shopping mall collapse that occurred ten years prior. Kang-doo, a former aspiring soccer player, struggles with physical pain and the trauma of losing his father, while Moon-soo, an architect who also lost a sibling in the disaster, attempts to suppress her grief by focusing on her work. Their paths cross when they are both hired for a new construction project on the site of the former tragedy. As they work together, they begin to uncover the hidden truths of the past and find solace in their shared pain. The series explores themes of trauma, resilience, and the healing power of human connection, as the two protagonists navigate their complicated feelings for one another while confronting the lingering ghosts of the accident that defined their youth.