Movie / kdrama about movie star fighting criminals???

Hi, 

I don't know if I'm crazy but can anyone tell me the name of the movie or kdrama where an actor fights bad guys but he thinks it's fake? or does something like that not exist?

I know he has long-ish hair
He is good at fighting
it's in a building or something ( no not the raid lol )

I saw a trailer somewhere, sometime ago, at this point I just want to know if I'm not crazy lol