Kaoru is a studious boy who has to live with relatives who care nothing for him. He is a loner, and when he gets in a social situation he has panic attacks. At his new school, he tries to get to the roof to cool his head, where he meets his class' delinquent, Sentaro. Sentaro calls him 'Richie', and intends to bully him and milk him of his cash. Ritsuko, Sentaro's neighbour and childhood friend as well as the class president, is the only one who dares to go up against him, and she takes Kaoru to her dad's record store. In the practice room underneath, Sentaro is drumming -- jazz. Kaoru is a classical pianist, and Sentaro is dismissive of that. Of course, Kaoru starts to study jazz, and before they know it, the two of them have regular sessions in the basement and become friends.
That's the set-up. What the series is really about is growing up together. There's a love triangle between Kaoru, Ritsuko and Sentaro -- and with the addition of Yurika and Brother Jun, it even becomes a love-pentagram. There's the various family circumstances, the various insecurities, the various problems that teenagers towards the end of the 60's had to deal with. There's a lot of character development: you see the characters literally growing up. It's a great coming-of-age story, of how Kaoru found his inner compass.
The visuals are nice, the music is great, and the story highlights the kids and their relationships in a rather intimate setting. It's not spectacular, but stories like this don't need spectacle because they shine with the humanity of their characters, just like Usagi Drop does. I'll give this an 8.5.