Parasite Choon: 'Choon' the heroine with wacky and girly sensibility, lives with her best friend Ga-hee in her boyfriend's house, and is absorbed by three generations which struggles but eventually loses its goal.' Choon' who couldn't shake off her worries about the future, happens to hide in a mansion by chance and plans a meticulous operation with her best friend Ga-hee and boyfriend to be a perfect parasite, but the story of three people who don't know the upcoming storm and their huge price to pay awaits.