Mitsuki IS in love with aya, she said before and probably thinks that aya won't see her as a crush anymore because she now knows that mitsuki is a girl. Mitsuki doesn't get it aya's love because she isn't a normie and she is clueless about aya's or others showing affection romantically. I'm sure she will express her love for aya through music.
I hope their friends and family helps them in someway too
They're both for sure in love, but both convinced the others feelings are platonic. Even if there wasn't the "please be my friend" scene when Aya clearly was expecting something else, gay kids just tend to be really awkward in this exact way. There's implications for this series that they'll eventually get split up and reunite after a time skip, what with Joe's arc and a certain illustration on the author's twitter, and while that's "a trope" and "disappointing" it's also something I've seen multiple queer couples do IRL. I've done it too, but only as a hookup lol. The vast majority of queer people still don't come out until college at the earliest, so even if they felt a real connection to somebody in high school they don't act on it until some later reunion or chance encounter.
Ikr, it's so confusing to be young and in love with someone as same gender, bcs I had myself a "best friend" and I didn't know it was love until 4 years later. 6 years later we talked again after years of being separated (we had a fight, and guess for what. Yes, jealousy) and she confessed to me but at that time we already had our other love ones.
It was so hard to understand bcs I'm bi and for her it was so clear what she felted but she was afraid to lose our friendship.
I really don't want this to our aya and mitsuki but well, I appreciate how the author is somewhat realistic