Lee Sung-kyung stars as Kim Bok-joo in the series. A successful and ambitious weightlifter, Kim Bok-joo draws her strength from her father, a former athlete. Kim Bok-joo is a cheerful girl who stands up for her rights in any situation, especially when she faces injustice. Sometimes, she is like a boy who can't control her anger and gets into fights. Kim Bok-joo lives with her father and uncle, who is a poultry seller. Nam Joo-hyuk plays Jung Joon-hyung in the series. Joon-hyung, who attends the same sports academy as Kim Bok-joo, is a handsome swimmer with great talent but not much luck. Despite the challenges in his life, he never loses his cheerfulness. Jeong Joon-hyung lives with his aunt, uncle, and cousin, and his aunt and uncle own pharmacies. The story begins with the conflicts, secrets, and of course, love between these two swimmers. Jung Joon-hyung falls in love with our weightlifter Kim Bok-joo. Kim Bok-joo is so dedicated to fulfilling her father's dream that she has no knowledge or experience of love until she meets Joon-hyung. Kim Bok-joo, who trains hard every day to win a gold medal, finds her life changed by the encounter with Joon-hyung on a rainy day.
