The ghost of a student who died at a Korean school comes back to seek vengeance and protect her friends.

The ghost of a lesbian high-school girl takes revenge on the people who used to bully her. And another young girl finds her old diary detailing her love and rejection when she was alive.

A staircase leading to a schoolgirls' dormitory usually has 28 steps, but sometimes a 29th step appears. Any wish you make while standing on this step comes true, even if it must come true in the most horrific way possible.

While practicing after hours in her high school, an aspiring singer is mysteriously killed and her body vanishes. Her invisible ghost is trapped in the school, but her best friend is able to hear her voice.

Four friends pledge to commit suicide together but while standing on the ledge, only one of them actually jumps. Her ghost begins to haunt the remaining friends until the pledge is fulfilled.

After being appointed as the vice-principal of her alma mater, Eun-hee becomes plagued by hallucinations. Branded a troublemaker by the teachers, Ha-young hears strange sounds coming from the school's dilapidated restroom.