The Masked Lover - The FL is pretending to be her twin sister, a mafia boss / president of a company that is now semi-legit. The ML is a cop who blames the FL's sister for the death of his informant. He goes undercover as the FL's assistant in order to bring her down but he sees that the FL is very different from the cold mafia boss he knew previously. They quickly become close, and the FL asks the ML to pretend to be her husband (because her sister's daughter wants to meet her father). The ML asks if it's an order, and says he must refuse. For work, he can work himself to the bone for the FL, but for relationships he cannot betray his heart. Later the ML learns the truth about the FL's identity and meets the FL's niece. When the niece asks the ML if he is her father, he decides to play that role. So he doesn't accept fake marriage with her when he thinks she's someone else, but he does end up playing fake father-of-her-daughter once he knows her true identity. And that naturally turns into a legit relationship between them pretty quickly. The FL's mother also asks the ML to prove his loyalty to the family and company by agreeing to marry the FL. He refuses again. A short time later, he proposes to the FL himself without being forced.
