Ah, Hirunaka no Ryuusei.
I'm going to start off with the bad news, and move into the good news.

The Bad News:
This manga suffers from a love triangle which, in most cases, I don't enjoy whatsoever. The story is quite typical, and to be expected. That being said, re-reading this manga has given me a bit of a different perspective. Although there is still the regular tropes to expect, the author handled a good transition in story, especially in the 8th volume.

The Good News:

The characters, for the most part, aren't too bad. We have the protagonist, Shizume, who is an interesting character but falls to the same demise as the rest of the cast: poor writing. I think Shizume suffers the most from OOC situations, in order to forward the plot in the direction it has to go. She is still unique from most protagonists in shoujo manga, including her personality and features. Yuyuka is also an interesting character, who develops quite a bit during the progression of the manga -- and I have to say that her progression was very satisfying. Yamamori did a great job making the supporting characters actually matter: everyone who was close to Shizume was given time and space to develop overtime as well, instead of remaining static. The last character I want to touch on is Mamura. It is not often that I feel so deeply for a character, and Mamura is one who I have grown attached to. His part in the story is wonderful, his characterization is wonderful, and his friendship with Shizume is something to be envied. He is not pitied and he is not made into a helpless third wheel. You see how he changes over the course of the story, and with the combination of the art, it is truly a pleasure to read.
The number one reason I recommend people read this manga is for the art. Yamamori Mika is an exceptional artist. Her characters are all unique, and she creates incredible atmosphere with the use of figure and negative space. Her strengths also include eyes, hair, and clothing. There are a lot of close ups of a character's eyes closing, and they are gorgeous. All of these things contribute to the greater aesthetic of her work. Maybe this isn't the best manga story-wise but it is probably the most beautiful series I've ever read. It is absolutely inspiring. If shoujo isn't your thing, I would still recommend sifting through this manga simply for the art. It IS that good.