Song Soo-jung, a producer in her third year at a small company, specializes in filming human-interest stories and dreams of becoming Korea's own Oprah Winfrey. She is portrayed by Jun Ji-hyun, and as months go by without pay she begins to push the edges of her pride to chase a big story. One day, she heads out with the company camera to chase a piece about a lion that supposedly won’t eat, hoping it will be a hit enough to secure her future.
On her way, she runs into a robber but is unexpectedly saved by a man in a Hawaiian shirt who introduces himself as Superman. He claims he can’t access real superpowers because “bad guys” have put kryptonite in his head, yet he refuses to let that stop him from helping others and from trying to save the world. Soo-jung sees the possibility of a sensational documentary and, with a little bending of reality and a touch of fabrication, she crafts the film titled “Superman Saves the World”, which storms to ratings success.
An X-ray later reveals something lodged in the presumed hero’s skull, and the mystery deepens. The true story behind this Superman, whose real name is Lee Hyun-suk, is revealed: two great tragedies haunt him and harden his belief that he is a real superhero. As a boy, during the Gwangju Democratization Movement, Lee’s father is killed and Lee is shot in the back of the head, yet survives with the bullet still inside him. Years later, in a car accident, his wife dies while his daughter survives; in the wreck, Lee tells his daughter that if she counts to one hundred, he will become Superman to save her.
A catastrophe unfolds when the bullet in his head triggers a seizure just as he runs toward a burning car, and the vehicle explodes with his daughter still inside. The crowd does nothing to help, sealing Lee’s belief that he is Superman. He lives with that conviction as he tries ever more daring rescues, and Soo-jung becomes drawn into his mission by following his example. After a heroic effort to rescue a police officer trapped under a burning car, and a subsequent attempt to save a child from a collapsing building, Lee jumps from a window with the child and falls, striking his head. He seems to fly and travels back in time to try to alter the past by saving himself from the childhood bullet, but the dream ends when he awakens in the present to the reality that he died from the head injury sustained during the rescue.
No one in the crowd helps him, and the hospital scene hints at something chilling as an organ is prepared for donation. Soo-jung, moved by Lee’s sacrifice, begins to reexamine what truly matters in life. She recalls a line Lee often used when they first met—“Strength doesn't open big iron doors but a small key.” This realization reshapes her, turning her away from calculating, frosty ambition toward a gentler, more meaningful approach to her own life and work.
