A girl who has been childhood friends with a guy named Baekhyun, is held back one year due to an awful accident. She doesn't know why she was held back, but it seems as though everyone else does. Baekhyun is now her only friend. The character learns that her accident may have more of an impact on her life than she thinks. Jin Kyung discovers secrets, history, and mistakes that have happened. And now her life has been turned upside down.