Hmm, I think I've chosen the other answer since the walkthrough said it set the flag for Allison's ending and there's nothing about Mira's ending, but that makes sense given their situation. Guess I'll have to backtrack a bit to change that, though I'll keep this save for Allison's ending.

Thanks.

Edit: Still not there, sadly. I've tried both choices just to be sure so there's something else to it. I dug a bit and found out I couldn't load my saves made during Allison's story 14 (where you choose between Allison and Mira for the sex scene). Saves before and after that load fine though, so my save might be toast from that point on for Mira.

I'll have to replay that scene as well and see if that works.

Edit 2: Yep, that fixed it.