Twelve-year-old Young-ha has been living with her divorced mother, but goes to live with her father so her mom can make a new start. However, when her father suddenly disappears, Young-ha has to return to her mom. Now 15, Young-ha has a new father from her mom's second marriage. Mom works hard to support the family and keep up appearances. Meanwhile, Mi-jin, Young-ha's best friend and cousin, is sent away to an uncle after losing all her family. Young-ha has nothing to do but pity her. At 19, after finishing the college entrance exam, Young-ha spends many hours with her new dad since mom is so busy. One day, while alone with her step-dad an unexpected event occurs. She tells her mom about it. Sub-zero Wind is a film about a girl's growth. The series of trials Young-ha experiences make her realize she is alone in confronting the world. Meanwhile, from the mother's perspective, her struggle to make a new family is falling apart. For the characters in this film, life's failures throw them into a world of loneliness.