Story: For once, I actually wanted the storyline to slow down a little. I so thoroughly enjoyed the plot and the intricacies between characters that I wanted to see more. But, with what I was given, I can't really complain. The story is of a lonely boy that's been on the move his entire live. Now that he's finally been allowed to settle down, he's a fish-out-of-water in post-war Japan. The story is a whirlwind of love, friendship, music, and coming-of-age. At one point, the protagonist comments that his life is like a jazz number, full of improvisation. The plot seems a little like that sometimes, but somehow, it remains easy-to-follow.
Animation: I've only seen a couple pieces down by this studio, so I can't say much about their animation style as a whole. This anime, however, had very subtle animation points, such as the smallest widening of the eyes to convey serious emotions, to the harsh movements of Sentaro's drumming. The facial features remind me a bit of the older Ghibli style, actually.
Sound: Do you like Jazz? Because that is what this anime is all about. I loved both the opening and ending themes, but the interwoven jazz really tied it all together for me. There are some references to period pop pieces, like "Some day my prince will come" and "My Favorite Things", but mostly it's all about the jazz. And usually, I would critique on a musical anime's ability to convey the style they chose, but I'm too busy swaying to the riffs.
Characters: The main cast, Kaoru "Richie", Sentaro, and Ritsuko are given a rich, beautiful storyline all their own. They are given grand, sweeping emotions that made me attach to them. Their emotions, their feelings were the main points of the plot. The side characters, like Jun, are given backgrounds, depth, and a little flair that makes them more than simply background (which I have seen far too often). I think my only critique is how quickly the characters change emotions, but with the plot flying past, I guess that's to be expected.