I really hope we get more backstory into A, because she was great in Sept (which, btw, you should really read, because at this point I don't think you'd be able to understand the main story without it)
@Me for me, the happy ending would be:
they get back together -> they start to go out -> they kith -> turns out THAT was the condition for switching back -> happily ever after!
Really love and hate at the same time about all the sadness (from loss of the brother and everything stemming from that) just... seeped into everything.
Finally they address the whole "isekai" thing. Yes, Iris knew stuff from the "past" life but this is the first time they're confronting it in perspective of Iris' identity.
@Vasqueztion the "hero" reminds me of the asshat "heroes" from Shield Hero - thinks wayyyyy too highly of themselves, and always looking down on the "main guy"