Do you remember how they looked, this trope was popular a bit back so there's a few ones
Does the fl had red hair and ml was a duke ?
https://www.mangago.me/read-manga/the_duke_s_servant/
I could only remember this one
They're Chinese not Korean story but I appreciate these manhwa you mentioned I'll check them out
mulan? jkjk, but i do wanna know too that sounds funny lol
There's a story I read 5 years ago it was a straight historical manhua the fl pretend to be a man to get closer to the ml(I think he was a prince and they were in war or something) the more closer they get the ml started falling for the fl without knowing she's a female I think the truth reveals when they tried sleep tgt and ml couldn't find fl's dih