"Sunday Seoul" is a film with three nonsensical episodes: THE WEREWOLF: A high school student Do-yeon who is the victim of bullying in school, is the main character of the first episode. He is not good at studying or at fighting. One day, an unexpected change happens to his body. THE VISITOR: On a pitch-black stormy night, a woman is visited by a stranger seeking shelter. The stranger eventually, is revealed as a serial killer on the run. THE YOUNG ADVENTURER: Seeking revenge for his father, a son embarks on a journey in which he encounters a young girl by chance and starts to learn martial arts.

Agent Lam (Tony Leung) sets out to track a pair of plates used to make fake American dollars. When he discovers the plates, they are conned out of him by enigmatic US Embassy workers Owen (Richie Ren) and JJ (Shu Qi). With the trail now leading to Korea, Lam sets off in hot pursuit. There, amidst the dangerous and glamorous urban landscape of Seoul, Lam finds himself confronting an underworld crime boss known as the Polar Bear, head of the biggest counterfeiting organisation in Asia.