Cinderella and the Four Knights

[spoiler alert]
both couples previously met when they were younger and had exchanged a token then gets lost later on as they grew up. Fast forward to being adults, the female lead faces personal problems and meets their lover. They start out on bad terms but slowly fall in love as they get to know each other. Both male leads have lost their loved ones and struggling with personal issues (becomes strong when they fall in love with their lover).
Both dramas seem to also have various characters that protect the female lead. the lead female character is loved by everyone except for that 1 girl (who then accepts them later on).
the theme of art/creativity is in both dramas. TBS has music & design, while CFK has music & fashion.
The difference would be that TBS feels more like a real-life love story, while CFK is a fantasy love story between the rich and poor (reason why it's called cinderella). Both in my opinion really cute love stories. Both made me cry and laugh.

Poor, strong-headed kind girl who gets to "live" with rich arrogant boy because of his grandpa who gets helped by the girl.

Both dramas are about sons/grandsons with different personalities and backgrounds living in the same house for the sake of inheritance/place of heir. Both involve romance whereas BSM is a more idol-kind of drama.

They both have similar plots but they both kind of take different paths to get there. The comedy is pretty good in Cinderalla and the Four Knights. They both have a similar feel to them.

Both stories are about a rich man and a poor woman and how it is possible to have a romance even dispite the financially gap.

Both are about a poor FL entering the house of a rich grandfather and his grandson(s) and becoming involved with one of the grandsons.

Both have a somewhat strong female lead
Both has four handsome boys
Both has a "bad boy" who becomes nice with female lead
Both has two boys in love with the female lead
Both might or might not give you a mild SLS.

If you like one, you might like the other

although the plots are a bit different but it gives the same feeling. boih have the rich and poor theme. MLP is more comical and easy to watch while CATFK has serious elements . great stories in all. definitely give them a try!

They are both about a girl chasing her dream and she some how ended up living with four handsome guys I personally loved romantic princess it was fun and sweet

Good romance. You have *bo-shan's* and main caretaker instead of butler. Shes gonna suffer for accepting to be a babysitter to BIG (adult) baby's. Worth of watching X"DDD

Both the shows have a similar romance trope though the plots are different!!!
FL and 4 ML characters

They both give off a similar feeling. I find resemblances between ji woon and hanazawa rui, but also between hyun min and domyouji. The storyline is somewhat similar as well.

Both have "reverse harem" genre with handsome male leads ................................................................................................................................................................

They both are reverse harems(one girl with multiple if guys in her life). The tones are very similar. But CAT4K is a cohabitation drama whereas 7FK is an office/endorsement drama.

They are both reverse harems and have similar tones. Have similar cliches: love triangle(or square), hard working female lead with spunk, multiple male leads, etc.

Both female leads are in high school who work hard to be where they are today. But the reasons are different. But both are in debt.