She Was Pretty (2015)

As a young girl, Hye Jin was impossibly cute and had a comfortable life with her wealthy parents but since her teens, her looks and fortune changed abruptly and now she is living with her friend rent-free and working as a part-time clerk at a convenience store. One day, her childhood first love, Sung Joon, contacts her wishing to meet her, but recognizing Sung Joon has grown into a handsome and fit man, she quickly hatches a plan to have her pretty friend meet him in her place instead. After luckily landing a full-time job, Hye Jin is surprised to find Sung Joon as her boss, who is adding insult to injury, treating her with disdain and contempt.