Yu Sijin, who was not taken seriously by her parents since childhood, was abandoned when she was eight years old and given to the Cheng family. Cheng's parents tried their best to treat her, and she gradually felt the warmth of the family. Just when she thought she would be happy like this forever, her adoptive father died because of her. She stayed up all night with guilt and became increasingly withdrawn. At this time, she met a boy who appeared in her life holding a cat. She thought he was leading her out of the darkness...