Hm. I like the idea as such, but I don't really think this is the time for something like that. Perhaps we can do that a little further along the story. Kaoru could become a sort of swordsman-fanboy and always run to them when something happens. After a while they get pissed off and decides to teach the kid a lesson.

Or something... 

My point is that we're on a timed mission and should prioritize that for now.