I swear I'm not gay, but the boys are just so wonderful.
This technically qualifies as a reverse harem anime, but it is a good one. Yona is easy to relate to, yet strong, and serves as a great vessel for an idealized version of the viewer. The main supporting cast is full of wonderful boys. They will make the viewer think "why can't all men be like these guys?" they have a very diverse set of personalities, and the writers did a great job of making them all different from each other, without making any of them a person the viewer would want to avoid. Furthermore, their devotion to Yona makes perfect sense, given how wonderful she is. Of course she is no Mary Sue, and has plenty of flaws, internal conflict, and character growth.
The narrative is driven by characters, setting, and conflict, as a good narrative should be in my opinion. There are plenty of minor supporting characters, as well as the main ones, and the conflict is ever present. Conflict can come out of anything from multiple characters who want to do the right thing, but having conflicting information from one another, to the occasional malevalent villain.
The biggest problem with the show, however: it only shows the early parts of the story. The full story exists in a comic that the show was adapted from, but no one knows if the rest of the comic will be adapted. PLEASE WATCH THE SHOW! The more popular this story gets, the more likely we are to see an adaptation of the whole thing.