So we are up to 4 in count.
I included a pic as I have three dramas in mind that I couldn't find a pic for, so included JCW wearing one as an example; not from any particular drama he is in.
Fedoras and floppy hats don't count. Yeah, it is very specific in type as I was wondering how popular a look it is.
4. Introverted Boss: - Support character Jang Se Jong (the one who came up with the worst theatre idea) wore one he came back as a celeb.
5. One Dollar Lawyer - cannot remember which character it was.