Well, she appeared on the movie The Last Princess where she was a late joseon princess. She's in hanbok and she's a nice character.

I'm so happy with this pairing!!!! I love Kim So-hyun, she's my fav actress. She is going to be 18 next year, so she's not a baby anymore. And Yoo Seung-ho looks so young, so I'm happy he was paired with someone who looks younger than him (with Go Ara and Park Mi young he looked like their younger bro).

I'm going to follow this drama news closely!

Too biased, about what or who?

Can it really be avoided though? If we didn't want an underage pairing then Kim So-hyun Yoojung etc. should stop being casted as leads and wait until their old enough. Or they should choose a drama with no romance.

People love to forget that there underage actress still has to play romantic scenes with the grown-ass male actor. If they were dating in real life, that'd be reprehensible. But if she is forced by the scrip to repeatedly fake intimacy with him in her workplace, that is totally fine.

I need help to understand all this underage thing.
Maybe it's a cultural thing for me, but in my country, and though the adult age is 18 year old, the society views teen girls such as 16 and above (to be 18) already grown up women.
I never seen on tv or alike things (or even on real life) a girl underage (16-17) and a boyfriend who is (perhaps 23 and above) get criticism and controversial topics.
We get on tv lots of youth tv shows who got love and made many teenage girls/boys get to stardom. In our tv shows there is always a love line with other characters, older or not, they get and I never seen criticism for it.
So I'm not used to all this topic of an underage woman (which for me 16-17, they're not just teens, they're grown up women physically) getting all negative criticism for playing with a male lead who is older and adult.
So I think it's a cultural thing maybe, how society views it. And I think my country is somewhat traditional in many ways, but we're western and maybe we're subjected to other border views as well.
Most girls now lost their virginity before 18, and many had lots of boyfriends even on their teenage years.
Of course I think 13/14 years old, they are still too young, but our society view women 16 and above grown up women, and even my grandmother finds normal 16/17 year old women that are dating guys, and most of the time their are on their 20s. I think what people still talk here is HUGE age gaps for example 20 years difference, or 10 years if the woman is older than the guys.
So it makes me kinda confused about all this thing with underage when the girls are physically grown up women. But again, it's just a cultural thing...I guesss...

He's only 23 years old. Acting-wise, they're both perfectly fit to be together (if you watched Missing You, you'll know what I mean). The age thing is just a matter of persepectives, really. Besides, its a historical drama and in that era age didn't matter when it came love.

And yes, So Hyun's ability to have a good chemistry with her leading men is no joke. I'm more than happy and excited for this drama to air soooon~~!

(P.S: I think Kim So Hyun is the only teenager actress boardering on roles older than she actually is? Or am I wrong? Nonetheless, her portrayals are top-notch, taking Let's Fight Ghost's Kim Hyun Ji for example.)

to think about it,
I think it because the other era already has its glory side represented greatly but I hardly think that joseon has a good one in politic theme, Six flying Dragon? but it's like early joseon (most of the notable one is the love story and you can remind me if my memory is wrong),
I can only remember dae jang geum, yisan, Damo, Iljimae and MDBC (perhaps) for the popular title from joseon era ( Tree With Deep Roots and SKK probably can be included),
but I hardly find any representative for Joseon that wasn't about love,

then we have damo, the ballad of seodong, seon deok, jumong, Haeshin, The Kingdom of The Winds, Gyebaek, the legend , Princess Ja Myung Go,Six flying Dragon and the before 2000 saeguk that tell us the story before Joseon and the gat era,
even Empress Ki is like early Joseon,

so personally think Jose on is good but they have to do a better story telling,
Nirvana in fire and many Chinese palace dramas is more like Joseon and I find it entertaining,

* you can correct me if my information is wrong, I probably forget something important,

Joseon seems like the favorite era when it comes to sageuk. It's history was well kept (Annals of Joseon) compared to the earlier era with only references here and there to go by since the original historical documents were destroyed.
Yes, Joseon will never die lol. The highest rating sageuk ever (64.5%) was based on Joseon's Doctor Heo.

Most of the fusion sageuk these days are just dress-up based on novels, webtoons etc.
KBS is the only hope for a more conventional sageuks based on the actual history like "Jeong Do-jeon" (Joseon) and that was 2yrs ago. It's more expensive to make so I doubt they'd come out with another epic traditional sageuk in the future.