In a Korean school, students are regularly beaten and mistreated by their teachers. However, the spirit of one pupil, who died ten years ago, periodically returns in the guise of a new girl, thus able to gain a revenge on the culprits.

While investigating the school files, the frightened teacher Mrs. Park startles and calls the young teacher Eun-young Hur, telling her that the deceased Jin-ju Jang is back. The line dies and Mrs. Park is attacked and killed by a ghost. On the next morning, the teenager Jae-yi Yoon waits for her friend Ji-oh Lim, who has the ability to call the spirits, and they begin a close friendship. The abusive and aggressive Mr. Oh, a.k.a. Mad Dog, is the substitute of Mrs. Park and prohibits Ji-oh to paint and compares the performances of the pretty So-young Park and the weird Jung-sook Kim, raising a barrier between the two former friends. Miss Hur misses her former friend Jin-ju, who committed suicide, and while trying to contact her, she discloses a dark secret about the past of her friend and Mrs. Park.—Claudio Carvalho, Rio de Janeiro, Brazil