Ik that’s it’s a Korean manga.
So, the MC was severely mistreated by his family all except for his older or twin sister who sometimes sneaks in food for him.
One day, they have him pose as his sister to get married to the ML of the neighboring clan under the pretext of a peace treaty but really they wanted him to assassinate the ML.
The MC was very tiny even though he was about I think 13-14 at the time (around there) the clan he’s from has a special power where they are immune to poisons or something like that? Later in the story, he gets wrapped up in this silk like cocoon cause he’s getting “older” or shedding or something that has to do with his clans powers I’m not sure.
The ML treats him very nicely cause ya know it’s a little kid, and even proposes they run away together.
Ive looked through the entire Gender Bender tag and I can’t find it maybe I might have missed it TT
I think it was a manhwa, there's this "king" that lives in a big castle high up in the mountains and every year or so he asks for brides and the brides would compete to be his wife. The Uke had a twin sister and she was to be sent to be offered but he decided to take her place and dressed up as a girl while the sister had to run away so they wouldn't find her. The king ended up being some Vampire, supernatural being and he was looking for the reincarnation of his lover by looking for a cresent or moon like birthmark somewhere on their body.
This fits the description. :))
http://www.mangago.zone/read-manga/i_ren/
I wonder how hes gonna handle the situation once he becomes a big name actor. Obviously ppl will try to look into him and maybe theyll find out that be was just a normal dude or maybe someone that he went to school with will say something about him. We know the whole thing about him being from abroad is a lie so Im wondering whats gonna happen once that lie is exposed.
I can give you spoilers I read the novel before