If I remember well, in one of the
Hana Kimi versions (
To the beautiful you/Korean version or the
2011 remake) the girl poses as her (twin?) brother, but you don't really get to see the brother.
In
Rooftop Prince, you have a lookalike/reincarnation story, where 3 of the main characters both appear in the Joseon & contemporary story.
In the beginning
You who came from the stars, the fact that the young version of the main female character looks exactly like a young girl the male main character has met hundreds of years ago is also quite important but it's not really emphasized beyond that.