This drama is a jewel in disguise and perfect for getting out of a drama slump. Though Cinderella and the 4 Knights lives solely off its main female lead and all the relationships in the drama itself, it's something you should give a try. 

Storywise C4K could not be more cliche. Seriously, pretty much everything about the story was typical rom-com. The plot makes you think you'll get a total reverse harem story but that storyline dies pretty much in episode one since everyone who watched a few rom-coms before knows who ends up with who or at least who doesn't end up with the other person. That is actually also the only reason why I watched it. If it was really a harem story I would've skipped the drama.
Characters
The female lead is amazing. There are plenty of headstrong or stubborn or earnest female leads in the history of dramas, but Eun Ha Won takes that to a whole different level and she does it in a charming way. I was seriously afraid she was gonna be over the top but she was like...a real human being I guess? Someone who didn't seem out of a drama but more like a normal person, you'd meet on the street, and that was so refreshing.
The other characters are pretty cliché, as well as there is a lot of character development you can expect beforehand. Another thing I have to praise though is the fact that finally we have a second female lead that is kinda a love rival but also a friend. She doesn't hate Eun Ha Won and wants to be friends with her, which I think is like a total turnaround from other dramas.
Otherwise the drama totally lives off its relationships and the interactions that come with it. Funny comebacks, lovely couple scenes, and so on and I spend pretty much every episode laughing my head off or being glued to the dramatic scene.

For me C4K is a jewel in disguise because you expect your typical rom-com and you'll get exactly that but in such a refreshing and bubbly way you'll want to giggle your heart out. I totally recommend it for people in a drama slump!!!