PSA: Minor retcon, chapter updated.
The paragraph in the end note talking about the smell that was on you has been updated to this:
"The plan called to have Canvass sniff you over as you left the city, to make sure no trackers were on you. She smelled something weird on Kei that freaked her out, although she couldn't precisely identify it. It was on Hazō and Kagome as well, but probably as a secondary contact, she thought. (i.e. it got on Kei and then you interacted with her enough to get some of it on you.) All three of you scrubbed until it was gone."
Turns out, hey, who knew, Kei was with you. Doh.