Finally got to see this at Anime NYC this past weekend. It was good but damn did it make me ugly-cry, with snot & everything...which isn't fun in a KN95 mask. It was entertaining to watch it with an large audience and their impromptu reactions to the on screen developments.
The only part of the story I didn't like was the romantic rival, Tsuneo's co-worker at the Dive Shop; I don't feel like her love for him was given sufficient development in the story before her ugly confrontation with Kumiko/Josee in the wake of the death of a certain adult character. It definitely provoked a loud and hostile reaction from the audience I was with. It just feels kind of tacked on and it could've been better written. I guess the creators were going for the shock value of it, but I don't think it quite works in execution.
Also the final scene with Tsuneo and Kumiko ("Josee") if of course a repeat of their very first encounter, nearly beat for beat. I get it because movie logic, but it is a little over the top, plus Tsuneo is technically still injured, having just been discharged from the hospital...
It's not a perfect movie, but it is gorgeously animated and the story is emotional torture porn that punches you repeatedly in the feels. I was nearly sobbing during the (2nd) children's book narration by Kumiko ("Josee")....for the kids it's just a fantasy story but for us in the audience it's a fictionalization of the real-life ordeals experienced by Kumiko & Tsuneo and how he inspires her and in turn her hopes for him and his future. That was golden; I loved that scene so much.
The best thing about Kumiko ("Josee") is her poise and quiet dignity she maintains in the face of adversity.
I feel like Ninomiya's story should've been handled better, because she just comes across as so cartoonishly evil in some scenes. If they'd actually given us a more sympathetic look at Ninomiya then the quasi-love triangle would've been that much more painful and dramatic. Tsuneo is a little dense when it comes to girls and their emotions. He can't seem to grasp that by letting Kumiko see his workplace including the fact that he works in close proximity to a very pretty girl his own age would be upsetting to Kumiko and fill her with jealous rage and insecurity. He has no clue in grasping either girl's feelings toward him sometimes.
So in sum a flawed but still beautiful movie.