Pretty Young Sister.

Ji-yeong and Woo-hyeon is on a fun, casual relationship. However, Woo-hyeon finds out that his friend Min-soo likes Ji-yeong and decides to be a stepping stone between them. Will Min-soo and Ji-yeong be able to date after many twists and turns? Or will Ji-yeong go back to Woo-hyeon's arms? The story of two men surrouding Ji-yeong's heart begins.