It seems a human really could inspire it, because one inspires it by succeeding, right? By making a grand gesture and having it work? So Bren, the most willing to "go native" so far except maybe for Ian, is the most likely to be able to inspire it - but then he won't feel it, he won't have the visceral reaction to seeing someone else have man'chi to him, and he won't have man'chi to anyone.

I concur that the quartet leaving Bren unaccompanied is really strange. Like I said on the non-spoiler post, there had to have been a way for a gentleman to accept an invitation that included his security, but Bren didn't know what it was, or know that it was expected that he do that - did he insult Banichi et al again by not including him in the acceptance?