I've seen it so many times but it finally clicked last night that Karen died in the opening scene of the movie that's like a little microcosm of what the entire movie's themes are about, she died at the start, and she spends the entire movie until The Final Line "dead", put in mental purgatory (led there by Nana via the otherworldly train, who is now trading roles by bringing about the change of life for everyone that Karen talked about in the TV show but the movie proves she never truly in her heart believed, it's like Nana got resuscitated and now it's Karen's turn in the morgue) and now it's Karen's turn to relive her past in a loop the way Nana did so she can come out putting her money where her mouth is and actually understand and accept that life is constant change wanting to move forward, and all the other revues of the movie with the other characters are like acting out different thematic arguments and ideas for why Karen has to change via their own interpersonal dramas, and when she faced Hikari again she THOUGHT she had it all figured out and could finally move on with her life and regain her humanity not just living for Hikari, but she couldn't because the reality of having to step outside the narrative she'd made in her own head for so long felt like asking her to die, and in the shock of that she DOES die, until Hikari's love made her mind believe she can try one more time, hence all of The Final Line and Karen finally coming out the other side being the last one to lose their plisse jacket and escape the urge to rot in the past
*also the fact that Karen died at the start in a manner similar to how the final line ends suggests her issue itself is looping, repeating because she keeps coming up against the same fundamental problem of not being able to let go and move on and be her own person again and again she keeps coming back to it in a cycle and Hikari or the image of Hikari in her mind keeps stopping her from changing, so she circles back around over and over until the movie ending is finally the instance where she lets go and stops repeating that mental anguish in her head
