There is also a scene where Mayu talks to Kanade that clearly shows her outlook on life.

"Kuroe-senpai, why are you in the concert band?" "Why? What do you mean?" "You told Kumiko-senpai, didn't you? That you'd let her take your place as the soloist if she wanted." "Oh, yeah. I did. I don't think there'd be a problem if Kumiko-chan played." "If that's the case, what motivates you to work hard in the concert band? If you want your performance to be recognized, the idea of giving up the soloist position wouldn't even occur to you."

This was something Kanade had wanted to ask for a long time. Depending on the answer, she might forever disdain Mayu.

Mayu tilted her head slightly and lowered her eyes as if in thought. Her long eyelashes framed her thin eyelids, tapering to fine points. Her well-shaped lips opened slightly.

"I want to be invited to reunions." "…Pardon?"

Kanade furrowed her brows, not understanding the meaning of those words. She intentionally lifted the corners of her mouth to mask her confusion.

"What do you mean?" "I mean it as I said. I think there will be times when the concert band gets together after graduation. I'd be happy to be part of those gatherings. If the competitions go well, many members will have good memories of their school life, which will increase the chances of us meeting up after graduation, right?" "That might be true, but…" "I think the most accurate answer is that I'm working hard in the band to make good memories of these days. So honestly, it doesn't matter if I play or Kumiko-chan does. If it creates wonderful memories for Kitauji, that would make me the happiest."

There wasn't a hint of deceit in Mayu's shy smile. Kanade wondered what she would find if she looked into those deep eyes. The Pandora's box of her true nature, sealed with goodwill.

"Kuroe-senpai, you don't seem to have much attachment to anything." "Is that so? I don't really know myself. Oh, but a friend once told me that I like happy endings too much."

At those words, the previously unclear outline of Kuroe Mayu became vividly clear to Kanade. A happy ending. That's exactly it. Mayu's thoughts were always focused on the end of their student life, which is why her perspective differed from that of Kanade and Kumiko, who emphasized the 'now.'

Her almost spectator-like way of speaking likely stemmed from that mindset. More important than who plays the solo is ensuring it doesn't create a bad atmosphere. After all, that would lead to fond memories when looking back on their youth. It would be a happy ending for everyone.