If you look hard enough, there actually are a few MOOCs in Japanese on those two platforms. I can’t remember what they are though.
I’ve also found this platform, but I’m not sure if many of these courses are about the topics you’ve mentioned:
At a lower level (academically speaking), you can also watch stuff like NHK for School, which targets Japanese schoolchildren from the primary to high school levels. Some of it is childish, sure, but I have to say that I found the simple explanation of what the Constitution was and why it matters pretty interesting:
And of course, since basically every country in the world prioritises its own history in school, you’ll also have plenty of material on Japanese history.