OK...I looked it up. :-)
https://www.viki.com/tv/1205c-sungkyunkwan-scandal
Of the two actors I like best:
This one, Crazy Horse, is:
https://en.wikipedia.org/wiki/Yoo_Ah-in
My Guy, the one who swirls around and who is in “Descendants of the Sun,” is:
https://en.wikipedia.org/wiki/Song_Joong-ki