A knife is pointed at the heroine's Il-young throat from the very first images of the film. This motif will be developed all along the film, both in a literal sense (there is a certain taste for bladed weapons) and in a metaphorical sense. Han Jun-hee is a former assistant director (Ba:Bo, 2008) and screenwriter (The Gifted Hands, 2013). Walking in the footsteps of Bong Joon-ho’s motherly monsters, his Coin Locker Girl is under the reign of the Ogress Mom, a sort of Cixi, the dowager empress of Chinatown in Incheon, caught in the turmoil of adoption.
The main theme penetrating Coin Locker Girl is ‘survival’, and many characters express that theme in their own way in the movie. I want the audience to focus on two unique female characters, Il-young and Mom, since it isn’t common for a noir genre film to have female main characters. 
Korean film directors nowadays often feel bitter about the fact that there are so many real life situations that are more appealing or tragic than the movies they make. I suppose that is the reason why noir and thriller films, which are the genres that can easily emphasize the ugly part of society, are continuously produced nowadays.
Kim Hye-soo, as Mom, is one of the most influential actress in Korea. Starting her career from the 1980's, she is an undoubted top-celebrity and has great reputation for her breathtaking performances. She is one of the most powerful actress who knows how to express the extreme and control the audience. While Kim Hye-soo represents the today of Korea’s movie scene, Kim Go-eun, as Il-young, is the rising star who will reign in the future. She is drawing public's attention through her unique visage and the untypical acting she shows in her movies.”