A boy transfers to a school in the countryside, where he finds himself attracted to a mysterious girl. The girl lives alone with her mental patient father and enjoys skating alone on the lake at night. Villagers and classmates spread rumors about the girl, but the boy doesn’t care. Then one day, her father disappears and the boy becomes witness to suspicious activity. Other than a few documentaries, this is Choi Jin-seong’s first feature film. Steel Cold Winter is no normal teenage love story.

A sickly girl Ju-ran transfers to a new sanitorium boarding school to regain health. But she discovers that students are disappearing and notices abnormal changes happening to her body. She suspects the school for what’s happening and tries to discover what secret is hidden.

In-Soo (Kang Ha-Neul) has a special gift to see ghosts and has become isolated from other students because of this. He transfers to a high school in a rural area outside of Seoul. There, In-Soo meets a female ghost (Kim So-Eun) at the high school and forms a friendship with her. Meanwhile, classmates disappear one by one.