The movie centers on two siblings, an 11-year-old boy named Chan-yi (Yoo Seung-ho) and his little sister So-yi (Kim Hyang-gi). Abandoned by their mother, they are left to survive on their own. For his sister's 6th birthday, Chan-yi decides to give her a dog. He sneaks into a house of an old couple and steals a newly-born puppy, which she's been longing to have. Even though they are poor, they were happy. But everything changes after a tragic accident; So-yi dies and Chan-yi is left on his own to survive the streets.
Choi Chang-hyeok (Park Shin-yang) is driving in his car, when he suddenly finds himself followed by the police. In a nice car chase he tries to get away, but as his car emerges from a tunnel it goes over the side, down a cliff and he is killed in the burning wreck.
A lonely chef with a speech impediment takes a job as a professional killer in order to raise the money he needs for an operation on his tongue. Known as "Killar", he and his partner "Ballet" make a rule to only kill rude and impolite people. After killing each one of his victims, "Killar" goes to the same bar where he meets "Her", a woman who becomes attracted to him. His life begins to unravel after he and "Ballet" kill the wrong person by mistake.