Kim Hana was in absolute bliss: she was about to marry her boyfriend, Byun Baekhyun, but her perfect life was shattered when Baekhyun lost his life while trying to save her. She felt like that was the end for her. However, with the help of an angel, she was given the opportunity to go back three years and stop Baekhyun from meeting her, hoping that would be a way to keep him alive. Will she be able to save him or lose a love of a lifetime?