In “Mask Girl,” Kim Mo-mi aspires to be a celebrity, but her dreams are hindered by her appearance. Despite societal pressure, she becomes the online persona “Mask Girl” to live-stream performances. A series of events, including exposing her boss’s affair and spreading rumors, leads her to connect with Oh-nam Ju, a colleague who’s ridiculed for his looks. Mo-mi’s actions result in accidental deaths, betrayals, and complicated relationships.
Kyung-ja, Oh-nam Ju’s mother, seeks revenge after her son’s death, unknowingly targeting Mo-mi. Mo-mi’s close friend, Chun-ae, concocts a rivalry story to protect her. Mo-mi’s daughter, Mi-mo, faces isolation due to her mother’s notoriety. She befriends Ye-chun, who hides a secret motive. Mi-mo’s life spirals when she learns the truth and confronts Ye-chun.
Mo-mi’s time in prison involves defiance and transformation, influenced by Kyung-ja’s vengeful actions. Kyung-ja manipulates Mi-mo through tteokbokki sales, spreading rumors, and orchestrating events leading to chaos. In a climactic encounter, Mo-mi’s sacrifice protects Mi-mo, while Kyung-ja meets her end at the hands of the police.
In the end, Mi-mo finds refuge with Ye-chun’s family. Mo-mi’s story ends tragically, with her death shielding Mi-mo from Kyung-ja’s wrath. The narrative explores themes of appearance, betrayal, maternal love, and the consequences of one’s actions.