I think the preview shows Ye-jin leaving NHD. He was supposed to come to NHD's contest but I think something happened to his family and that forced him to leave. and separated for 3 years. And then will meet again.
She fits the character in the drama "Young Lady and Gentleman". She is such a good actress and got casted in a 50 episode drama. I think this is just the beginning of her successful acting career. More dramas for her to come.