For fake relationships/contracts, the K-drama Family's Honor! The main two characters, Dan-a and Gang-seok decide to pretend to go out in order to help Gang-seok's younger sister with her unrequited love for a male student who has a crush on Dan-a. (That sounds so incredibly contrived but the story manages to sell it, and I found it really entertaining.) Highlight is that the two protagonists are relatively honest about the chemistry they feel instead of being in denial about it. It's a really long series but one of the best I've watched recently. I have some episode reviews if you'd like to find out more.

I hope you get other recs because I like these rom-com tropes too. ^^