Synopsis：Lee Eun-yi (Jeon Do-yeon), working at a fast-food restaurant, lands a job as a maid in a wealthy household thanks to her early childhood education certificate. The master of the house, Go Hoon (Lee Jung-jae), is handsome, successful, and multi-talented; his wife, Hae-ra (Seo Woo), is elegant and charming, living a life of luxury and expecting twins; their eldest daughter, Na-mi, is delicate and adorable. This family appears nearly perfect and enviable. Eun-yi is humble and gentle, diligently attending to the family’s daily needs, and quickly integrates into this affluent household. Gradually, she begins to yearn for the life of a wealthy lady. Meanwhile, Go Hoon develops feelings for this pure-hearted woman. As time passes, their emotions for each other grow increasingly intense, ultimately crossing the line. The pleasures of the flesh overpower reason, leading them down a dangerous path...