These two are very similar and I'm surprised this wasn't recommended already~
- Male leads are extremely similar- rude, rich and always bossing around the FL.
- Male leads both have someone they haven't gotten over.
- Both are from the same era of kdramas so the humor is similar.
- Contract relationships in both.
- Enemies to lovers/Hate to love in both
- Both have similar pacing.

- Both dramas have unique energies that make them addictive.
- Both FL's have rare personalities. I wouldn't say they behave similarly, but they are uncommon compared to other kdrama female leads.
- Appreciation for the arts in both dramas.
- Elegant aesthetics in both.
- All rich leads, excluding the ML fro IOTNBO.
- They also share actress Park Gyu Young

Notable differences:
- It's Okay to Not be Okay has a immature FL and mature ML. It is the opposite for Dali and the Cocky Prince.
- Dali and the Cocky Prince is the lighter drama. It's Okay to Not be Okay has darker, psychological aspects to it.

*without major spoilers*
Similarities:
-visually impaired leads that are initially cold
-leads with art and music careers/hobbies (piano, songwriting, ballet)
-beautiful music
-cohabitation at some point
Differences:
-the korean drama has fantasy and the chinese drama does not

- Both couples are initially at odds in the beginning
- Both couples include one of them being royalty and one working in the palace
- Both of them have a palace conspiracy
- Happy ending and resolution for lead couple

differences:
- In Rookie Historian, side characters intervene and move the plot more than supporting characters in My Sassy Girl. Rookie Historian's supporting characters are also arguably more complex (imo).

Similar premise where main character moves into a new apartment and notices strange things happening. Both are Webtoon adaptations.
There are more key differences than similarities like:
- Strangers from Hell is darker and more of a psychological horror story.
- main character in Strangers from Hell changes for the worse
- Sweet home mentions monsters (of the supernatural kind i suppose), whereas Strangers from Hell has nothing supernatural, just weird and creepy.
- in Strangers from Hell, the main character doesn't have any true allies to help him, unlike the main character in Sweet Home
- you can probably watch Sweet Home with your light off, Strangers from Hell? maybe not so much