Of course, real ninjas didn't dress in black. That's a theatrical convention. By tradition in Japanese theater, stagehands or puppeteers dressed in black and were treated as invisible/nonexistent by the audience and other actors even while openly sharing the stage with them. Then some director had the inspiration to have one of those "invisible" stagehands suddenly reveal himself to be a ninja and assassinate one of the characters, making for a shocking (and kind of fourth-wall-breaking) reveal. The trope caught on, and black stagehand attire came to be thought of as ninja attire -- but only in fiction. Real ninjas just "hid" by looking nondescript. So given that the episode admitted that neither of the martial-artist combatants was genuinely a ninja, I wish they'd explained why they dressed in black. Anyway, Ryan wasn't very observant for a detective. It was clear that the heroic "ninja" had a feminine build, but Ryan called her "he." I also wish they'd given the victim a less cliched Asian-female name than "Jade." I'm not sure any real Japanese people would give that name to their daughter; it's not a word that renders very well in Japanese phonetics (the closest would be jedo or jeido). Unless her real name was Hisui and she translated it when she moved to the US. Still, it's quite a cliche. Speaking of names, I'm impressed by how accurate Stana Katic's pronunciation of "Michio Saito" was, which makes it puzzling that she used the same awful mispronunciation of "Yakuza" as everyone else in the episode. Come to think of it, I think I've noticed that about Katic before, that she usually makes an effort to give ethnic names accurate pronunciations instead of Anglicizing them. I noted the same thing here when she introduced Esposito. Maybe it's because she's sick of people mangling her surname. But apparently it's only with personal names, not group names.