Song Jiwoo has a crush on Lee Heewon but ultimately cannot confess her feelings and graduates high school without doing so. Eight years later, Jiwoo suffers an ankle ligament tear and ends up in the hospital for surgery, where she reunites with Heewon, who has become a nurse. After their reunion, they frequently encounter each other, whether by chance or fate, and Heewon begins to develop strange feelings for Jiwoo. A story of a second first love, loving the unfulfilled first love once again.