High School Roots & Tragedy: Yoo Hye-jung is dropped off by her abusive father at her grandmother Kang Mal-soon’s rural home, where she meets Hong Ji-hong. Inspired by Ji-hong saving a pregnant woman, Hye-jung studies diligently with the help of Jin Seo-woo. However, Seo-woo's jealousy triggers a school scandal. Shortly after, Kang Mal-soon dies during cancer surgery performed carelessly by Seo-woo’s father, Dr. Jin Myung-hoon. The cover-up and Ji-hong's forced departure leave Hye-jung alone and determined to seek retribution.
Present-Day Climax: Thirteen years later, Hye-jung is an elite neurosurgeon at Gookil Hospital, where Myung-hoon serves as hospital director. Reunited with Ji-hong, Hye-jung investigates the sealed malpractice records but faces expired legal statutes. The narrative peaks when Director Jin develops a life-threatening cervical cord tumor. Because of the extreme surgical risk, only Ji-hong and Hye-jung can successfully perform the operation, leading Seo-woo to kneel and plead for her father's life.
Resolution: Upholding her medical duty, Hye-jung performs the marathon surgery alongside Ji-hong, saving Myung-hoon. Humbled, Myung-hoon offers a sincere apology, giving Hye-jung spiritual closure. Seo-woo reconciles with Hye-jung and enters a romance with Pi Young-gook. In the series finale, Ji-hong proposes to Hye-jung along a flower-strewn path, culminating in her romantic confession.