The Cursed Lesson (2020)

Online fashion model Hyo Jeong faces the imminent threat of being unemployed because of the younger and more fashionable generation coming after her. While replying 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 an 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.