Don't get me wrong her personality shifts are still a little too sudden I can agree with that much, but honestly the problem has never been Hanesaki as much as it is the terribly written characters surrounding her her whole life. To be honest, I was never watching this show for badminton or sports because sports anime are really just... boring on their own. Its the characters I care about.
Now if you were "raised" by a psycho-mom, encountered a psych-rival, got replaced by a blonde bimbo, and then literally everyone who represents all of these traumas comes back to haunt you LIVE not on Television, but on stage in your backyard, forcefully, I highly doubt you will be mentally stable either. Pink haired thot, blonde thot, no brain "mom" all are beyond TERRIBLE characters. Her mom especially is not a character but a plot device because nothing she does makes sense.
However Hanesaki being a total ass to everyone after being absorbed into the sport and all of her old wounds being dug up... I'm not a Badminton loli so I can't relate on such a level, but personality shifts and mental breaks because of old wounds being dug up by the people who caused said trauma are real enough to me that I can empathize with Hanesaki.
Though someone did mention that they don't even write her in a way that you can empathize with her, which I can agree with. In fact there was just no real redemption for her character being dragged down by the poor writing by the end with how her internal conflicts are resolved, as well as the fact she forgave her mother. If this show was written properly I would have definitely cried instead of sighing when she thanked Elena for being with her all that time.
Maybe if blonde bimbo was an overseas transfer student that her mother seemingly doted on too much while she was sick and her mother dies in an accident during said doting, everything would've panned out much better as a backdrop for lingering trauma regarding badminton and her relations to blonde bimbo and pink goth.
I feel like there's a world where even the ending might've been OK if there was proper build up and characterization of Hanesaki where she gradually resolves her internal conflicts and moves past her past and lives life because there's more to life than badminton, and there's more to badminton than winning. She doesn't forgive all of the bad characters forced onto her life, but she faces them with a clear heart and clear grip on her own life and where she wants to take it not being driven by anyone else's motives.
But I suppose if the writers could write this, they wouldn't need to hinge on plot devices for "characters", and resolve conflicts the same episode they appear, or leave said conflict festering with no proper development given in the mean time.
Still I believe Hanesaki as a character did nothing wrong and I only hate the garbage writers for making everyone around her insufferable thots or plain useless to the plot. Nagisa's alright yeah I guess. She's generic sport MC done pretty decently, but that's all she is to me.
