^ as said in the title, I think what really sets this series apart from the rest of the stories in this genre is that it actually feels realistic. How both of them are close as childhood friends is evident by how comfortable they are in each other's presence and also brutally honest with each other when they have to be. But breaking out of that comfort zone into becoming lovers, the awkward yet sweet journey it is because underlying the new relationship is their former more deep relationship as childhood friends... yup, I think this one's done it right.
Don't get me wrong, there are a bunch of stock characters and cliched setups here and there, but there are certain moments too which really made the characters resonate with me. I think my favourite character out of everyone is Akira. Poor boy is so sweet and innocent, yet wants so badly to break out of the (i wouldn't say "friend" cuz its worse than that) brother-zone, that I find him really different from all the other shoujo male heroes out there.
Plus, the piano thing isn't a gimmick. Lots of chapters deal with the characters' insecurities regarding advancement in their piano skills, and it very effectively develops the characters, especially Akira's, throughout.
So yeah, I'd say that there are certain chapters that lag and make you go "oh whatever, I'll finish this some other time", but suddenly it hits you with these sweet moments that it makes you want to keep reading, cuz their friendship/love is that believable. 🙂