PP is a BL short drama while K is a woman-man love drama.
Yet, both has something to do with insomia, sleeping together, romance and mature scenes. Honestly, even the characters of the main leads is similar. anyway, if you like one of those dramas and you are open minded to genderless love between man to man or man to woman, you will find tha the dramas have the same vibes.

Both drams have a strong male lead and a female lead he love dearly and protects her, he is somehow smarter and conning in order to get what he wants from the female lead. In both drama there are various romantic scenes that are quite speacial and uniqe. EL in my opinion is much better in every aspect, but TOYOL somehow gives the same feeling.

Both about two differents worlds and the female lead moving from her world to another. FL meeting someone who helps her in need and there is a secret about the 2 worlds that the leads are working to solve.

W contains romance, while Derailment is still ongoing drama so I don`t know yet if it has any romance at all.

Both about a prince falling for a commoner,
K2H is with more action and strong female lead (not just mentally).
PH is with more comedy and more romance screne, its easy going

Both are about BL couple, when one of them is connected to the mafia, and the other dosen't. I didn't see MDGO yet, just a trailer but it seems like MDGO is more easygoing while NM is darker, with more action.

yet, I still find the both comprable.

Both are about BL couple, when one of them is connecte to the mafia, and the other dosen't. I didn't see MDGO yet, just a trailer but it seems like MDGO is more easygoing while KP is darker, with more action and intimacy.

yet, I still find the both comprable.

Both dramas have a ML CEO and FL who works for him. Together they try to solve problems in the company.
Both have some kind of romance tension, but only in DMN the romance gets progressed while in HAY the tension is kept but actually they don`t even kiss >_<

Both drama connect the love of the FL to food and some romance tension.
I find that WWDS is much more draker since it has a lot of mysterious plot but if think that if you liked NTAINR you would still like my recommendition since both FL has motivation and drive to cook that capture you in both dramas and keep your intrest.
Both also have Arrange marriage - not for love but for the sake of saving the food resturant.
I feel that there is a bit more romance in WWDS but since NTAINR is still airing, it's just a guess.

- both having a ML being a male mermaid in high status.
- both FL are human. In both the male stays in the FL home.
- in both ML is really thirsty for water in abnormal way, in both the moment he touch the water he grows his tail
- the TSNTSS has more romance, and is longer.

the male lead play in both dramas.
In each drama he plays in, he gives his special touch of sex appeal that can make each drama become amazing.
seems like he has a grand future ahead of him, I am actually looking forward to any drama he acts in.

anyway more similarities are:
- FL hepls ML
- FL is shy but hardworking pesrsonality
- sex appeal

TML and NM are very similar, you can dinf in both:
- twin sisters/ brothers with totaly different personalities, when one is a leader of mafia or a group that fights for the law being applied equally, and the other is really pure and senstive.
- both sister/ brother replacement make the ML to feel the difference and be attracted to them.
- both has some kind of a mistory - what happend to the other twin so the other twin has to pretend to be his twin to discover.
- both are really intresting and has romance scenes (though I wish for more).

I think that if you enjoined one, you will enjoy the other!

while AC is the long version
EWS is somehow the shorter version.
so what they have in common?
- FL madly inlove with the ML
- another woman who loves the ML and gets the ML's mother support.
- breaking up the marriage
- meeting many years afterwards, the FL secretly gave birth to the ML'S child and raised him/her on her on.
- the ML insists on remarriage.