Hyung-su graduated top of his class in high school and is on his way to Seoul University to study law, supported by his mother, who runs a hole-in-the-wall restaurant near a train station.

By contrast, Myung-su works as a bouncer at a local brothel and helps out in his mother's restaurant, but is happy to trade places with his brother whenever there is trouble.

Jung Joon-ho took on the dual role of Myung-su and Hyung-su to further his skills as an actor, and said, "When I read the script, I really liked the story and wanted to star in the film...

He prepared himself by studying the performances of other actors playing double roles in films, such as Jeon Do-yeon in My Mother, the Mermaid and Park Shin-yang in The Big Swindle.

Prior to the launch of the film, Jung noted that he focused more on the character of Myung-su, feeling that the personality of Hyung-su was expressed less fully than he intended.