Regarding a certain dissenting view:
IMO!: It's a story about two juxtaposing outcasts being brought together by a mutual, gentle empathy. And not about, say, I dunno... what some may interpret to be a sociopath that uses high-school power-dynamics to manipulate a classmate into submission. Which is sad. : C
Empathy, yo'. Gotta cross-reference character with what appears to be the author's intent.
El examplé: I felt the most important lines were on p. 11/12
Khouhai: 'I'm sad.'
Senpair: 'A-about what?'
Khouhai: 'About everything!'
If the story were told from Khouhai's perspective it would revolve around how she is unhappy and feels isolated, but is both motivated and pleased by Senpai's perseverance - yet, unbeknownst to her, the Senpai feels much the same way. In the end the pair are brought together by that which causes their respective unhappiness: The Senpai that's so bad she's bullied into quitting is encouraged to stay and be coached by the talented Khouhai that feels removed from her peers.
Ultimately the Khouhai remains cold and anti-social, the Senpai insecure and lacking confidence - but the narrative suggests, in amongst all their unhappiness, they've each found a personal sense of acceptance and understanding in one another's flaws and kindness. +Yuri. Which is nice. : )
[Also: One cannot offer a dissenting opinion and, in turn, resentfully dismiss a further dissenting opinion on one's own dissent. That, yo', leads to arrogant hypocrisy.]