The Time We Were Not in Love follows the lives of Oh Ha-na and Choi Won, two childhood friends who have shared a deep bond for seventeen years. As they approach their 30th birthdays, they find themselves navigating the complexities of adulthood, career pressures, and the lingering question of whether their platonic relationship could ever evolve into something more. The series explores the 'in-between' space of friendship and romance, highlighting the fear of losing a lifelong companion if they choose to cross the line. Throughout the series, the protagonists face various romantic entanglements with other people, which serve to test their loyalty and reveal their true feelings for one another. As they encounter heartbreak and professional challenges, they remain each other's primary support system. The drama delves into the nuances of long-term intimacy, the pain of unrequited love, and the realization that the person you have been looking for may have been by your side all along.