Am I the only one who thinks Miyabi is way healthier for him
She just seems like a narcicist who chased fame over those who loved her, ended up learning the bad parts of becoming famous (the ammount of insincere attention) and has crawled back to the person that gave her sincere attention, but is still too much of a narcicist to admit it. So not optimal, but basically one heart to heart and a few apologies away from becoming normal.
Hizumi does seem to have way more bagage at the moment, but that's probably just a consequence of being the main character since she has to be the one with the deepest backstory and motives. She'll end up getting "fixed" to some extent or Shinba will just accept the way she is and that will be it if I had to guess.
I may be biased because I currently like Miyabi's character more (as per my other comment), but I'd love to see a manga with a character like her as the MC. Outside of maybe villainess reincarnation/isekai, redeemed narcicist who learns their lesson is an extremely underused trope for a romance female MC for some reason even though it isn't super rare for male MCs.
It feels like romance manga female MCs can only have more "virtuous" types of bagage like trauma or social anxiety and things like that instead of regular negative personality traits that they can fix when they self-reflect as they grow up. It kinda perpetuates the idea that good people were always good and just misunderstood and bad people will always be bad and irredeemable even if that wasn't the intention. It is one of the things that has always irked me about romance manga even after a decade of reading.
Crazy how shonen probably has more realistic personal growth stories than even seinen romance lmao.