Once taken her job because of her appearance, a confident and enthusiastic woman, Hyo-jung visits a mysterious yoga institute run by an ex-actress where her radically changed friend told her to go. At the intensive training course, a young yoga master, nani explains to Hyo-jung and four other girls that only one person who masters the course most successfully can get the secret of ultimate and immortal beauty. there are five rules for them to follow during the one week course: 1. do not eat, 2. do not take showers within an hour after the class, 3. do not look at the mirror, 4. do not go out of the building, 5. do not call anyone. As the training goes on, girls get tempted to break the rules caused by hidden craving of each girl’s and Hyo-jung starts to sense there is something about this institute and an actress who doesn’t get old…

Strange rumors start to spread at the catholic girls’ high school after Unjoo committed suicide one night. Unjoo’s younger sister Jung-un who attends the same school gets suspicious about Unjoo’s death. After persistent investigation, Jung-un finds out that on the night of the incident, Soy, Eugene, Eun-young, Unjoo, the four of them had tried to commit a joint suicide after making a vow on blood. But the three are still alive, and only Unjoo had died. the desire, jealousy, and lies behind the pledge of death between the four girls are revealed, along with the hidden truth behind Unjoo’s suicide.