I don't understand why so many complaints. Maybe because you're reading a chapter every week, but it's only 4 pages. If you put everything together, it's like there are only 10 chapters? It's still at the beginning and you're already waiting for a kiss? Relax a little
This is the biggest of the cliches: a character appears that conflicts with the couple, which strengthens the relationship between the two, this person begins to be hated even by one on the side of the couple for being a "rival". Then everyone resolves and she becomes one of the beloved characters. It's a manga that talks about music from the very first chapter, they are teenagers who have never loved another girl before, so you can bet it will be very slow burn. Like, Mitsuki must think that Aya doesn't like her romantically anymore because she's not a guy and they will surely be afraid of ruining the friendship. It's always like this, go read something else
I also didn't understand why you think Aya hasn't listened yet? Isn't there a chapter just of Mitsuki singing to her?
Anyway, I'm freaking out with "Me to Her".