I was considering making an actual poll for this after seeing it in NA, but, eh. Gotta wonder what the non-talkers think~
I chose the ninth one immediately after reading each line. All I can think about with Aoi and Soji is that they came to Edo to kill someone/buy something/trade intel, she was somehow involved, and they went their merry ways. Besides, ninjas and their families were not confined to their villages. Just... tethered, as suggested in one route. Seems plausible to have crossed with Sion. They live in districts right next to each other, after all... I'd like to know more about Sion's brother, too.