"A one-sided love that ended without even a single confession turned into a 'bed partner' relationship." Sejin, who lived a mundane life as a high school teacher, reunited with Juhwan, her college crush, when he arrived as the acting chairman. While Juhwan's appearance causes cracks in Sejin's everyday life, he doesn't recognize her at all. A few days later, they meet again at a reunion and impulsively spend the night together. Rationalizing it as putting an end to her long-standing crush, Sejin tries to move on after that one night. However, Juhwan, intrigued by Sejin, proposes a three-month partnership... A role-reversed, realistic romance between two people entangled by a one-night stand.