I've been running into a lot of comments that I post, but they don't show up. It's annoying. You got one of those, so this is a second draft. ;)
I like the idea of having a ninja, but I'm going to stick to the time frame and setting for now. @michelle.gent talked about not shocking the reader out of the story. I think that could have the shocking effect. However, I do have an idea for something that would allow for input, and when I test that, I'm looking forward to hearing your thoughts!
I'm looking forward to reading more, you have much more experience than I, so it's great to learn from for myself, even though you wrote it to learn more for yourself. I guess this means @michelle.gent #story-mentor tag is doing what she intended. You don't improve if you don't try to begin with.