<Book Introduction> Seo Eun-gyu comes to the International Contracts Team after being promoted to the youngest deputy manager in history. Moon Da-won, a coworker who always lagged behind him and finished her rookie training in second place, is not thrilled to see him. However, this man, Seo Eun-gyu, is excessively kind to Da-won. After drinking, Da-won ends up sleeping with Eun-gyu. Ever since that night, Eun-gyu begs her: "Think of me as a toy. A sex toy to use when you're stressed." Slowly, she begins to feel drawn to this perfect man who is willing to give her everything.