The Cursed Lesson is a South Korean thriller movie directed by Kim Ji-han. The movie centers around Hyo-jeong (played by Lee Chae-young), a former online fashion model who is struggling to keep up with the younger and more fashionable generation. Hyo-jeong turns to cosmetic procedures and treatments to maintain her looks but still feels unsatisfied. She then hears about a mysterious yoga class that promises to help its students achieve a perfect body shape.
Hyo-jeong attends the yoga class with three classmates: Mi-yeon (played by Jo Soo-hyang), a boxer who is struggling to keep her body fit after a knee injury, Ji-won (played by Kim Min-kyu), who has an unstable mental condition, and Ye-na (played by Yoon Hye-ri), a movie star who is obsessed with her appearance. The yoga class is led by a mysterious instructor named Bora (played by Kim In-ae).
As Hyo-jeong and her classmates delve deeper into the yoga class, they start experiencing strange and disturbing events. They discover that the yoga class is not what it seems, and its dark secrets are slowly unraveling. Meanwhile, the police start investigating a murder in the neighborhood, which they discover was committed by a woman named Bo-ra, a former yoga class student. Hyo-jeong and her classmates realize that they are in grave danger and must uncover the truth behind the curse of the yoga class before it's too late.
The Cursed Lesson is a gripping thriller that explores the dark side of the beauty industry and the extreme lengths that people will go to achieve the perfect body. With its suspenseful plot and talented cast, the movie keeps viewers on the edge of their seats until the shocking finale.