If I were to be perfectly honest, I didn't expect much when I began reading this series. The idea of a single girl in an all-boys environment, or vice-versa, is a commonly used one in manga, and so I figured that this one would be no different from any of the others. I am happy to say that I was pleasantly surprised!
The story begins with Ashiya Mizuki, a girl raised in America who has come to greatly admire a high-jumper by the name of Sano Izumi. So, following her feelings of admiration, she moves to Japan and begins attending Ohsaka High School, which happens to be an all-boys school. For this reason she disguises herself as an effeminate boy.
The rest of the manga follows this sporty, naive, adorable girl throughout her time at Ohsaka. It outlines the relationships that she builds, romantic and otherwise, and doesn't have a single dull moment.
The character development is no less than fantastic. Throughout the story you see how everyone around Mizuki changes, how their feelings mature and their outlooks reflect this new found maturity.
The art work went through a similar metamorphosis. The beginning of the series featured a fairly typical older style of art work, which I felt didn't fit the story. However, by the end of the series I quite enjoyed the art style as it became more refined as each page passed.
But I will admit that this story wasn't perfect. In fact, I could name quite a few flaws. First of all, in the first couple of chapters Mizuki is discovered to be extremely athletic, and is initially chased by many of the sports clubs in a bid to get her to join them. However, after maybe 3 chapters of this, the entire of idea of Mizuki being asked to join athletic clubs is completely forgotten.
There is also the matter of untied ends. Many of the characters that one might think to be important had absolutely no closure in the series. They seemed to simply dissolve from existence. Same with some major events that was seemingly swept under the proverbial rug, never to be seen again.
Despite the flaws, I consider Hana-Kimi to be more than worth reading. I know that I don't regret my time spent with it. I will definitely be looking for more mangas like this one!