Wait, I just got a question pop up in my mind:
These girls are all in first year of highschool right? So they should be around 15-16 years old?
...since when was Yuzu playing in bands, that she managed to get people together for a band to perform in PAID GIGS, get a member fuck-up in such a way as to set up a latter plotline, then go to play in her highschool's light music club with her friend and also a bunch of DIFFERENT people (else it doesn't make sense Otabe wouldn't know about it - hell, maybe even Kinu doesn't know about it, even though she seems like a decently long friend of Yuzu with how they interact) and mess all of that up halfway(?) by the second term of her first year?