#parona

Hiya! Good to see you!

Yeah, I actually did know! In this case, words might not explain it, but pictures definitely do.

Although Hayase's and her successors are the only ones to reincarnate so prolifically, they're not gatekeeping that ability. Anyone (excluding Fushi) can do it. Aiko and Yuuki are probably both reincarnations of Bon's sister and brother, as well.

(And they have the same VAs, too!)

According to some extra material, Pokoa liked Kahaku's face so much that she decided to find a husband in Yanome, so the Aoki family is probably distantly descended from her. Yuuki and Torta look nothing alike, so that one was probably a decision that the anime staff made. But Fushi even alludes to Pokoa and Aiko's resemblance when they refer to themselves as Yuuki's sister in her form before correcting it, ahahaha!

Sorry for the tangent. But to answer your question: yes. There is a pretty straightforward meaning to Hanna and Parona's resemblance. Hanna is Parona's reincarnation, so they share the same physical characteristics, including their voice. But I also think the decision to put Hayase and Parona's reincarnations in such close proximity to each other was deliberate. Although they have a complicated relationship, they definitely don't hate each other. I think it serves to solidify the fact that Hayase's reincarnations don't inherit her feelings—whether those feelings are love or grudges.

Even if their actions might sometimes be outwardly similar to their previous incarnation's, Mizuha (and Hanna) have their own unique motivations that can't just be written off as genetic dispositions. Hanna being a reincarnation is supposed to remind the audience that she and Mizuha are their own people (not that it's working so far). So I also think a character analysis that treats Hanna as her own person completely independent of Parona is going to have far more meat on it than one that relies on her being a reincarnation.