The Handmaiden (2016)

During 1930s Korea, in the period of Japanese occupation, Sook Hee is hired as a handmaiden to a Japanese heiress, Hideko, who lives a secluded life on a large countryside estate with her domineering Uncle Kouzuki. But the maid has a secret. She is a pickpocket recruited by a swindler posing as a Japanese Count to help him seduce the Lady to elope with him, rob her of her fortune and lock her up in a madhouse.

The plan seems to proceed according to plan until Sook Hee and Hideko discover some unexpected emotions.