3 stars only because of Kim Soo Hyun. He is a great handsome actor with a lot of Carisma. The actor who plays his half brother was very good as well. The young prince and princess leads were outstanding. But I cannot believe that they cast that bland bad actress to play the love interest of the two male lead actors. It was painful to watch. In one of her close ups you could see her acne ( not her fault) but she had the same expression with her huge big eyes ( probably operated, a lot of Asian women have her eyelids worked on through plastic surgery) the plot was OK but Kim Soo Hyun kept me sort of interested. If casting would have chosen a prettier and better actress to be the love interest of the two brothers it would have elevated this K-drama.
The rest of the cast was just ok.