MiniTheatre

Min-ah (Kim Mun-sun) goes to an all-girls-school. One day she finds a diary. She finds out that the diary is shared by Hyo-shin (Park Yeh-jin), a quiet, but intelligent girl and Shi-eun (Lee Young-jin), an athletic student. The two wrote down messages for one another in the diary and brought their mutual feelings on paper this way. The friendship between the two seems to have exceeded the relationship of normal girls, but there is not much left of their mutual love for one another, as Min-ah finds out. The two evade each other as best as they can. Until, Hyo-shin suddenly commits suicide at school.
Rumors spread, that Shi-eun was at the roof at the same time Hyo-shin jumped off it. Although Min-ah witnessed this herself she comes to Shi-eun's defense and tries to get behind what really happened that day. Maybe Hyo-shin was pregnant? Did she have an affair with one of the teachers? Min-ah gets closer and closer to an answer, but somehow she has the feeling that someone is watching her. At school, several students talk about having seen Hyo-shin's ghost and the longer Min-ah investigates things the more she comes to the conclusion that her schoolmates may be right. However, what secret is Shi-eun trying to hide and what does Hyo-shin's ghost want?