Well, his mom did. http://www.soompi.com/2016/04/29/super-juniors-yesung-changes-his-legal-name/ 

Jongwoon-->JongHOON

It sounds weird to me, but he'll still be forever YESUNG.

I think I will leave him as "Jongwoon" in my fanfiction, at least until the name starts catching on to me haha. Please support me and read "Grow Up, Super Junior!", which I will update with a new chapter on Monday! :-)

Signing off!

~Nat