Moon Sung-hyun

Miserable and unsuccessful, a woman thinks she's lost all her spark, until one day, her spunky younger self appears in front of her demanding change. (Netflix)

Oh Han Byul leads an entertainment agency's PR team. One of her top clients is star Gong Tae Sung who does no wrong. They went to the same university, where he became her swoon enemy. They bicker but soon develop feelings for one another. (imdb)