That's a lot to ask from a local Japanese school or any person especially during these tough economic times. Perhaps during the "bubble kei" 90s, Japanese Schools would have the disposable income but not now.
Unless you have some sort of prior exchange program in place with a school in Japan, I'm not sure you will have any luck finding a school willing to pay for your airfare from Quebec, Canada to Tokyo (which starts from ¥102243/$1,148.80 USD/1,173.27 CAD per person) and host you, your wife and little baby girl for up to two weeks including room and food in exchange for a couple of hour long lecture/presentations on Indian Cree Culture.
You could try to contact the Canadian Consulate in Japan to make an offer (it might be worth inquiring) but I don't know if even they would be willing unless you are fairly renowned in the field or have published notable works on the subject matter.
Embassy of Canada to Japan