Kim Sun-woo is an enforcer and manager for a hotel owned by a cold, calculative crime boss, Kang who assigns Sun-woo to a simple errand while he is away on a business trip; to shadow his young mistress, Hee-soo, for fear that she may be cheating on him with a younger man with the mandate that he must kill them both if he discovers their affair.

When Seung-min was on his first year at the Academy of Architecture, he met Seo-yeon. She was a musician student, and Seung-min totally fell in love with her. Years have passed, and now he meets Seo-yeon again - she asks him to rebuild her father's old house.

Kim, a North Korean spy, lives in South Korea for 22 years and is contacted unexpectedly by his superior. His team plans to complete an earlier mission and steal the target's large stockpile of cash.

In a tranquil countryside hospital, radiologic technician Yeon-woo suffers from a mental disorder, the result of a childhood trauma in which he witnessed his younger brother die in a car accident. Won-hee, the hospital’s newest nurse, shows an interest in Yeon-woo, but he doesn’t appreciate her advances-he doesn’t even get along with hospital colleagues he’s known for years. Through a few chance encounters, they gradually grow closer and he opens up his heart to her. However, Won-hee has a secret that she hasn’t told Yeon-woo, and it appears that their love will never be.

Chae-geun is a driver for hire with manic depression. He often talks to his son who is studying in the States and tells him he would keep his promise. He does a favor by acting as a temporary fiancé of a single woman named Jin-hee, who works as a waitress at a restaurant he frequents. Her father, who was a victim of the Gwangju Uprising in 1980, shows him a gun he stashed away 39 years ago and asks Chae-geun to help him exact revenge on those who were responsible for the May 18 incident.