Whilst I'm not familiar with Choi Kang Hee, so don't know her other roles, I am not sure she was the right casting for this drama. Her chemistry with Kim Young Kwang didn't work for me, as the romance just wasn't believable, they were more like good friends. I am familiar with him, and whilst he did well portraying a lead male who's immature (but not completely clueless) and 'disinterested-in-the-company heir' type character, I'm again not feeling his casting quite worked, but that may be due to aforementioned lack of chemistry with FL.
Apart from the 2 company kitchen staff ladies, Geum-ja and Mi-ja, none of the characters stood out for me, and Ha-ni's younger self, I really found quite unlikeable.
It's also another one of those lead female characters who, whilst in her downtrodden mode, is shown as unattractive and frumpy. I get fed up with that, although I suppose it did show that a person's overall image has less to do with features (or even build) and more with hairstyle, flattering clothing and a little makeup; they worked wonders in her character's case.
Her family were also forgettable and treated her extremely badly, I thought, especially the awful sister.
The plot didn't fully engage me either and I lost interest quite early on, when she readily accepted being treated as a doormat. How the arrival of her younger (selfish, whiney and conceited) self, spurred her on to take a restock of her life, I honestly questioned, as she wasn't exactly a great role model.
I also didn't get the odd shaman character, or her younger self's return to the past, although that could be due to losing interest in the overall story.
Certainly not one I'd watch again and with so many other, better, dramas out there to see, not one I'd recommend either.