I doubt that particular word (katana) would be quite so permanently stuck in my head if not for watching Teenage Mutant Ninja Turtles a lot as a kid. That was a show that was for-sure aimed at boys.
The other places I could imagine having encountered it enough for it to have stuck are action video games and Japanese or Japanese-influenced action cinema & anime. I have some very confident guesses at how male and female interest rates in those would break down.
Sure, any particular person may buck their cohort trend, but that doesn't mean the trend's not there. Just as I'm sure there are some guys really into sewing or fashion who'd look at the original list and think, of the mostly-women part, "of course I know these, who doesn't?"
The other places I could imagine having encountered it enough for it to have stuck are action video games and Japanese or Japanese-influenced action cinema & anime. I have some very confident guesses at how male and female interest rates in those would break down.