idk about you but those are pretty intense indicators in relationships personally. Hiding something you always do together, going with other ppl instead or avoiding intimacy (even if its mitsukis fault, i get it). Then being vulnerable when drunk, i dont doubt it would stir up feelings in her. But at the same time, she needs to realise a relationship is deeper than liking someones music or kisses, the longer youre with someone you tend to know them better but theyre sort of… not really talking to each other about real things. and its clearly something theyre both struggling with.

i don’t really like how sumiko writes mitsuki bc it feels too fast and sudden for her to think aya doesn’t like her. like aya's worries make sense bc it's been building up for a while but for mitsuki, she only saw aya not inviting her to the concert once (which aya didn’t do out of fear of mitsuki rejecting her), avoiding sex once, and leaning on shu while drunk once. all of this only happened once, so how did mitsuki jump straight to the worst conclusion??
i feel like she should’ve been more concerned about why aya is avoiding her and just asked what’s wrong, but at the same time mitsuki has her own issues and insecurities so she tends to focus on herself first, which i get. it fits her character but it also feels a bit out of character sometimes. i swear younger mitsuki would’ve been more concerned about aya first before her own feelings.