When I enter in a other user profile, before add this person, usually go to the watchlist trying match our tastes for dramas. Can be only for title, nothing too dificult, only a thing who says (based on ours watchlist) how many compatibility we have with this other user.
One reason I have Mydramalist besides register my dramas (obviously) is for make some virtual drama friends, share things about dramas, memes (because in home this is really rare) so I thought this can be really helpfull to make this connection.
Bellow some ideas where you can put this:
Aside of our names in profile the percet of our match. (Like flagged in red in this photo)
When we enter in the watchlist, a page for the drama we have in commom, exactly the other dramalists. (Like flagged in red)
So, this is my suggestion, hope you liked! ??