The drama will depict the growing friendship and love between Na Hee-Do (Kim Tae-Ri) and Baek Yi-Jin (Nam Joo-Hyuk) from 1998 to 2021. In 1998, in a world that seems on the brink of disaster, two people—aged 22 and 18—meet for the first time, but end up hurting each other at ages 23 and 19. At ages 24 and 20, they learn to trust each other, and at ages 25 and 21, they begin to fall in love. Na Hee-Do is a member of her high school fencing team. Due to the South Korean financial crisis, the high school fencing team is disbanded. Overcoming all the difficulties, she joins the national sabre team.