I'm pretty sure it's like a identity switch, where one is a Royal and the other is a normal guy, kind of like that Disney Movie with Mickey Mouse xD the Prince and the pauper.
This drama is terribly bad ...like episode 1 is just staring....slow motion rotation camera, more Walking....staring...no talking. The same scene from 1000 different angles. I'm sorry if this is your favorite drama, but I just can't....it was just so so horrible in my opinion X_X
I Always found Touba Yu to be the same age or just a bit older than Jun so ...Jun should be the son of the oldest prince. While his aunt should be the youngest. If I'm not mistaken the two daughters by the King are the youngest Children (from what I've seen on wikipedia).
He is a really good actor. I feel this stregth and charisma from his acting in Princess Wei Young. I can't wait to see him in another drama! He is definitely an actor to keep an eye on! (Y)
Okay I'm 3 eps in and I honestly don't Think this drama is as good as I hoped it would be. it feels a bit messy and I really don't get why they had to make Joo Ri so damn psycho. It's hard to Believe it's realistic in the sense where she would laugh like a maniac and no one would find it strange. She has a screw loose but we are apparently supposed to still feel bad for her. ...um...sorry I just can't xD The main girl is bleh, everyone is kind of meh and the only person I kind of feel interested in following is Joon Young. I'm quite disappointed so far, as I was a big fan of White Christmas and I thought this would have a similar feel...hm...I'll continue it but I can't say this is a good drama. This is just my opnion though ^^*