Well, if you want to know the plot, I recommend you to go here for synopsis and some other details to find out who are the voice actors and trailers.
At first, I started watching this anime because of the characters. Then when I actually started watching, I find that the show is actually very interesting. The character development is one of the main thing that the anime highlights. The studio focus a lot on the character development and how the princes need to be put together since one of them will become a king one day and they need to be prepared for it.
Plot - This anime has an interesting plot with pretty visuals. I find the characters interesting since each and individual has so much interesting aspects that draw me in to watch this anime much more. Even when the current King was introduced, his character and his behaviours are like a doting parent even though he is a king of a country. The studio and the story perfectly portrays on the relationship between Haine and the four princes and Haine and the King.
Characters - Wow, just wow! I love how the characters grow. It was so breathtaking and heart-warming to see the characters learn and widen the scopes of their mind. It was sooooo nice to watch. What else do I need to say? I Just love the characters.
Music - I really liked the opening of this anime. The ED was okay but not my absolutely favorite throughout the series.
Art/Animation - The art is beautiful. I like the way the studio draw the background interiors and their landscapes.
Overall - This is the great anime to watch. This show showcases the friendship, the relationship between the four princes and the Haine, Haine's mysterious past with the King and the relationship between the four princes with the King makes me feel so fuzzy feelings all over my heart.
I recommend you to watch this anime. You'll experience the funny moments, the insecure moments, that warm fuzzy feeling from a character and this anime will make you grin like an idiot in the class. (well, that's what I was doing while watching this anime during my lectures) Also, watching guys that are cool is also not that bad for the eyes.
It was a 8/10 for me.