It's not much of a comedy but I think that
Secret Love Affair is a pretty amazing drama from what I've seen so far...
Definitely very mature and has amazing cinematography and acting, not to mention the music! If you're into classical music at all you'll absolutely love the soundtrack.
In terms of cinematography, it has a very interesting style to it that one would usually only see in movies. It appears to be very carefully crafted with a lot of thought put into it.. The style might seem a bit odd compared to the way most dramas are made, but if you admire quality work then I think you'll really like that about it.
The only think you might be a bit iffy with is the basis of the story, since it IS about an affair, and one with a 20 year age gap at that.
I suggest you don't let that get in the way of your decision to watch it though. Honestly, it's just so refreshing after watching drama after drama full of cliches and rushed plots and stereotypical characters.
It hasn't finished airing yet so I can't guarantee a great end, but so far it's one of the best dramas I've ever seen :)