Five years ago, when she was a new employee, Jeong Morae had a nightmare of a mentor — Seo Kangjae. Now he’s back, this time as an executive director with the prestigious SG Electronics bloodline… and her direct supervisor. Morae tries to avoid him, haunted by the embarrassing memory of a drunken one-night stand they had at a farewell party. But Kangjae calls her into his office, uses that mistake to threaten her, and makes an unexpected proposal: "Starting now, for exactly three months, once a week, twelve times in total. Sleep with me."