I still think Mitsuki's line being about Aya's love for rock/music makes zero sense. The one thing Mitsuki know for sure about Aya since the very first chapter is that she loves rock and music as much as she does.
I've also never seen any romance do that sorta "gotcha!" to the audience. Stupid misunderstandings, drunk amnesia, last-minute-cold-feet, all sorts of rubbish however plausible or not plausible, but don't think I ever saw any sort of serious author just go for a straight up troll of the audience.
It's one of those "plug-in endings" that's unfortunately weirdly common with manga. You could have gone on with the misunderstanding another ten chapters and put those two ending chapters there. Or you could have put those ending chapters in 10 chapters earlier. It wouldn't have made an iota of difference. ^^
. . . realized they'd plotted themselves into a corner and had neglected to come up with a way out.
Honestly it doesn't feel like they planned ahead much or thought too deeply about anything.
I mean, at some point they make a point of explaining the background of the archbishop and babylon as both being invested into the well-being of the refugees and working towards a common goal with their respective organizations - only to then find their differences causing them to become enemies that can't reconcile over the question of "how".
But at the end babylon-woman just goes "that's childish" instead of some sort "hey look, we tried that, it didn't work, what makes you think it'll go better now?" or aaaanyyything else that'd even remotely connect back to this obvious parallel development ^^;
Meh, dunno. Can't say that entirely convinced me; tone swings around too much, pacing seems kinda off balance - some things very rushed, others kinda drag. Bits feel like they weren't planned ahead. Ending is "people stand around and preach" and that's about it.
"The true hitman is the girlfriends we made along the way."
The promotion to just be a promotion with no strings attached makes Hiroko's refusal kinda weak. After Ayako's confession and everyone's reaction it seems kinda ... eeh to just "has a hang up from the past" be the only hurdle. It's obvious that company culture has changed. I think it'd have worked better had there been a bit more to it.