―The beginning of a night more brilliant than any moment Yurin, who had dedicated her life to the violin as the heir of a wealthy family, injures her left wrist in an accident as her family falls apart. Unable to play the violin properly, Yurin loses her will to live and attempts suicide, but is discovered by her close younger sister, Yeonhee, and barely saves her life. Yeonhee persuades the wandering Yurin to look for a job together at a factory located in a small provincial town, but for the two who have never even done part-time work, life at the factory is nothing but unfamiliar, and they constantly get caught up in small disturbances. In the midst of this, Yurin meets Eunha, the leader of the wrapping part, and becomes increasingly interested in Eunha's atmosphere, which is different from that of the other factory workers, despite being part of the factory. However, like the gloomy back mountain surrounding the factory, the shadows and environment surrounding Yurin do not leave her alone, and she constantly struggles between her feelings of attraction to Eunha and her guilt and compassion for Yeonhee...... * * * Jeong Yurin: After losing the ability to hold a violin due to the family's downfall and an accident, she falls into despair and loses her will to live. She meets Eunha, who approaches her with a special feeling at the factory where she got a job with Yeonhee. Hwang Yeonhee: As Yurin's close younger sister, she was by Yurin's side, but after saving Yurin, she decides to confess her feelings and actively intervene in her life. Kang Eunha: The leader of the factory's wrapping part. She smiles often and is kind to everyone, but there is a mysterious atmosphere about her. She helps Yurin out of a crisis and brings her into the wrapping part.