Se-yeon, who has devoted her entire life to her family as a mother and a wife, suddenly learns she is terminally ill. Knowing she has only 3 more months to live, Seyeon is determined to live for herself more than ever and decides to find her first love back in high school. She asks her husband the absurd task of helping her find her first love. Stunned as ever, her stubborn husband, Jin-bong, reluctantly joins her search. Throughout their journey together, Se-yeon and Jin-bong are reminded of the most glittering, beautiful moments of their lives together.