I fell in love right on the first chapter. I have a weak spot for mangas that use music to express feelings, too.
The characters are incrediblde. Sunaga is...I can't even describe him. He's persuasive, TOO sexy, mysterious, sadistic, perv...and yet he's just the type of seme I like. He has also a destructive and a hurt part that makes my heart throb.
But Akira isn't bad, either! I usually don't care much for the ukes, but I like Akira's super ego, and that he puts his pride before everything - it suits him! He's also determined, strong and fierce, not whiny at all! <3
Summing it up, what I like is how well-made the characters are. They are so psychologically developed that they could have been real people.
Also, I think the way they fell in love is beautiful. It's quite obvious that they were attracted to each other as soon as they met. Akira can hide it as much as he wants, but his body expressions shows just how much he's affected by Sunaga even before he makes it clear. And how thye're relationship makes progress so slowly...because even if they did have sex before they acknowledge each other's feelings, they understood each other since the beginning.
Oh, but I have to say, it did remind me a little of Gravitation, although Gravi is a much more childish manga. But I guess it can't be helped, everyone thinks of Gravi when it's related to music since it's become so popular...
The art, as usual from Tateno-sensei, is marvelous. Hot bodies, sexy/cute faces.
It did make a good impression on me, also because I loved even the other characters such as the band members!