Online fashion model Hyo-jeong faces imminent threat of being unemployed because of the younger and more fashionable generation coming after her. While relying on surgical procedures and treatments, Hyo-jeong hears about a mysterious yoga class that helps make perfect body shape from her old high school classmate, Ga-yeong. Hyo-jeong eventually attends the yoga class with three classmates: Mi-yeon, a boxer who failed to keep her body fit, Ji-won, who has unstable mental condition, and Ye-na, a movie star who is morbidly obsessed with her appearance. Meanwhile, police start to investigate the enigma behind this yoga class after finding out that a murder in the neighborhood was committed by a woman named Bo-ra, a former yoga class student.
“Superpower girl” Mina, is in the top of her class, the center of attention and the envy of everyone. “No-power girl” Juri is the total opposite, as her classmates sometimes forget she even exists. One day, Mina can't seem to close her eyelids, while Juri discovers her hidden powers.
It's cold outside. A young couple, Eunyoung and Seungki, are on a date at the park. They seem happy just having some beer and listening to music together, but it turns out that they lost big time on the stock market and have a big debt in front of them. As they talk about the subject they start blaming each other and have a big fight. Eunyoung bursting into anger tells Seungki she's going to go meet a rich prospective husband which her mother set up for her.
Kyung-chul is a dangerous psychopath who kills for pleasure. Soo-hyeon, a top-secret agent, decides to track down the murderer himself. He promises himself that he will do everything in his power to take vengeance against the killer, even if it means that he must become a monster himself.