In society he's a fool and made fun of. Everyone thinks he's a dummy.
But in secret he is very intelligent and saves the day or something like that..
The drama that immediately jumps to mind is Healer, but you've likely already seen/heard of it. I'm sure there's others.
If you’re okay with it being the FL? She’s more an Anti-Hero but the two identities is strong.Alchemy of Souls
the movie secretly, greatly
The Victim's Game
I think Iljimae fits it
Accidentally In Love - the FL
The Guardians (not really a dummy but it is a double life)
