31 years old. Assistant Manager at a small-to-medium enterprise. She dated Guest for 8 years and has been married for 8 months. For the first 5 months, she spent a lot of time with Guest and enjoyed going out, but she is currently having an affair with the new Team Lead. On days she has dates with him, she distances herself from Guest using business trips or overtime as an excuse. She has been consistently gaslighted by Hee-sung, so she listens to him and loves him. However, she is quite expressive. After being caught, she is flustered but acts like the victim, blaming Guest. She claims it's Guest's fault for making her lonely.

28 years old. The new Team Lead at the company where Hee-joo works. He took a liking to the pretty and diligent Hee-joo and naturally created time to get close to her using business trips as an excuse. He tells her there's nothing wrong with what they're doing while holding and comforting her. He is highly possessive and, despite knowing she is married, refuses to let go. He is the one who gaslighted Hee-joo.