Kyubin

It's not about that, but the fact that he knocks down two policemen, one teacher, leave the hospital with a patient, but nobody notice it. Unlike the rest of the drama, this scene was a bit off to me.

Well, it was VERY good, until Baek Sang Ho barged into Eun Ho's hospital room. The way he kidnapped Eun Ho doesn't make sense. That was messy but the ending was good though. It's still one of the best dramas I watched.

All the characters are so weird, anybody acting like them in real life would be called a crazy person ^^. Most of their lines are coming out of the blue. But at the same time, it's really nice. The relationship between Ha Won and Seo Woo is getting really more and more interesting and Jung Hae In acting is quite good here. Chae Soo Bin is good too, but she doesn't give the same feeling as Jung Hae In.

I agree. It's really unfortunate the way the story goes. The plot is nice, but even if dramas have their own logic, the fact that Sol Ah start falling for Hong Jo despite having longed for Jae Su during 10 years doesn't really make sense here.
Well, it's half-through, but I feel like I will not really like the futur development of the story.
Would have been nice if Hong Jo was like a little Cupid.

Well, it's kind of fun to watch, the plot was nice, and in the same time it's really annoying. All 3 main characters have unnatural, very stupid behaviors. The assumptions of characters because another one don't speak and they don't ask, so commun in K-dramas, is really annoying here. And the way the story evolves is a little bit disappointing.
(Also, when K-dramas will stop leaving houses with lights on everywhere, all the time ? Come on ! People don't live like that in Korea, it's so stupid.)

Ta Hwan / Hui Zhong / Ji Chang Wook ! Well, probably the character/actor that made me become a fan of K-dramas (well, you can guess by my profile... ㅋㅋㅋ). Really annoying, true, but so adorable, and kind of heroic.
I agree, it's a shame that Ji Chang Wook doesn't have more various characters to play. Hope he will play again in a sageuk, too.
As for my favorite historical characters, well, it's hard to choose but here is my top 5 for K-dramas and my top 5 for Korean historical movies :

5 - Goo Hae Ryung / Shin Se Kyung (Rookie Historian Goo Hae Ryung)
4 - Lee Bang Won / Jang Hyuk (My country)
3 - Shin Chae Kyung / Queen Dangyeong / Park Min Young (Queen for Seven Days)
2 - Ta Hwan / Hui Zhong / Ji Chang Wook (Empress Ki) and Clown Ha Seon / King Yi Heon / Yeo Jin Goo (The Crowned Clown) (Yes, couldn't choose between them !)
1 - Nam Sun Ho / Woo Do Hwan (My Country)

And special mention to Jang Young Nam as the Queen Dowager in The Crowned Clown, one of the best queens dowager of sageuks.

5 - Princess Song Hwa / Shim Eun Kyung (The Princess and the Matchmaker)
4 - Kim Seon Dal / Yoo Seung Ho (Seondal : The Man Who Sells the River)
3 - The King / Joo Jin Mo (A Frozen Flower)
2 - Prince Kwang Hae / Yeo Jin Goo (Warriors of the Dawn)
1 - Princess Deok Hye / Son Ye Jin (The Last Princess)

And she's Chinese, but Gong Li is my all time favorite as the Queen Phœnix in Curse of the Golden Flower.

Great. Really great.
It's as simple as this drama is. Slow, quiet, but also warm and just true. It looks real, authentic. The plot is simple (even if it will probably become more sophisticated later I guess). It can be boring, depending what you like, but watching this drama give a really good feeling. Like someone else said in the comments, it's great to watch a drama/movie where the actors can stay silent but steel give a lot of emotions. This drama is like that and Seo Kang Jun and Park Min Young are really good in it. I look forward to the next episodes.