Professor by Day, Master by Night

Lucy, a medical student trapped in the cycle of domestic abuse, finds solace in a secret dominant-submissive relationship with a mysterious man known only as "Daddy". Her double life shatters when Ethan Walton, a stern new anatomy professor with a voice identical to Daddy's, walks into her lecture hall. When her gambling-addict father tries to sell her to the mafia to settle his debts, Ethan rescues her at gunpoint and offers her shelter. As they grow closer, Lucy is torn between her feelings for the professor and her loyalty to Daddy. After Ethan pays $200,000 to save her from being auctioned at an underground SM club, they share an intimate night. Lucy misses their long-awaited meeting to care for her critically ill mother, and Ethan uses his connections to secure a life-saving kidney donor. In the final scene of the 30-episode arc, Lucy arrives at the hotel to meet Daddy, only to discover Ethan's shocking double identity.