2 chapters feels like too long to simply slam into a breakup/bad ending based on this convo, but not long enough to somehow figure out a way past this. Unless the entire final chapter is some kind of epilogue/time skip after they split?
For that matter, if this story is hurtling towards a doomed romance ending and always was, why tf did it spend 4 chapters screwing around with a plotline centered around the possessive coworker Ruriko trying to seduce Chiaki and split them up but them getting past it, if this is where it ends up 2 chapters later? Why bother showing that side convo after the confrontation in ch. 12 where the other coworker lectures Ruriko to not "sell herself cheap?" Other than sloppy writing, the only bad ending scenario that I could see making this make sense is if Miyako like fully leaves town after this, Chiaki keeps going to the shisha lounge and somehow eventually ends up with Ririko. Unlikely and hardly satisfying.