Jung Yup tries to find a job as a lawyer for a law firm in Seoul. It's not so easy for him, with Jung Yup being from a smaller city. In the meantime, he begins work at a child welfare center in his hometown. He goes with a co-worker from the child welfare center to the police station and meets 10-year-old Da Bin. The young girl reported to the police that her stepmother Ji Sook choked her around her neck, but there isn't anything Jung Yup is able to do. Da Bin is returned to her family. Da Bin and her 7-year-old brother Min Joon begin visiting Jung Yup at the child welfare center daily. He makes an effort to spend time with them to keep his job. Jung Yup is aware that the children are abused by their stepmother, but he is powerless to do anything about it.
Jung Yup then learns that he has been hired by a law firm in Seoul. Without saying goodbye to Da Bin and Ji Sook, he heads off to Seoul. One day, he receives a phone call that Da Bin has killed her younger brother Min Joon.
Min Ah discovers a scarlet-covered diary as she is hurrying to school. She has a brief hallucinatory experience when she opens it, initiating a series of strange occurrences which eventually draw Min Ah into the eerie world of the diary. In her desire to find out more about the diary, Min Ah feigns an illness, getting permission to lie down in the school's clinic.
There she witnesses the reunion of Hyo Shin and Shi Eun. The day in the girls' high school is half over, and the students are preoccupied with the trauma of getting their physical checkups. Suddenly their hustle and bustle are abruptly interrupted by a sharp scream which announces the death of Hyo Shin. Soon, her ghostly entity will linger over everyone's secret.