The entire point of the series is her being the chosen girl and ancestor (?) of the first king of the kingdom who had four dragon warriors with special powers on his side. By now you've guessed it probably but all those warriors happen to be handsome men as well and they feel a special connection to her the moment they see her due to the dragon blood of their ancestors. Their entire point of being born is to serve her and this makes all possible romance forced in a way, something I'm not a big fan of.
Yona herself stays for a large part of the series helpless too and even if that is explained by the fact that she was a spoiled princess who never left the palace, this is still annoying since it makes her come over as clumsy, naive and incapable of her own. She has undergone some character development by the end of the series which did impress me and I did wish for her to go further too. Unfortunately the series didn't continue and I do know the manga which is sad because by the end of it, this became actually a more decent show to watch.
