[Drama/Movie] Male/Female Charac. wiith Secret Identity

As the title says, I want to look for recommendations for a drama or movie that have the lead as someone with secret identity. It's okay if it's in Korean or Japanese, I'm okay with both. 

Maybe someone with a bad*ss fighting skills or a super genius character.

I've watched City Hunter so don't recommend me this and also Doctor Stranger. 

Thank you for your time reading this.

Tempest is about a woman with a secret identity.

Dramas: 
Cruel City (lots of secret identities in this one, not just the leads)
Iljimae & Return of Iljimae (most prefer the version with Lee Jun Ki, personally I like the second one with Jung Il Woo better)

Movies:
My Girlfriend is an Agent
Masquerade (not sure if you count it as secret identity, when a lookalike takes the place of the king)
Secretly, Greatly

And I second Bridal Mask :)