Oddly enough, a few images on there have comments in (Japanese) along the lines of “this is not allowed, reported.”
I feel like that’s more of a meme than anything, like the FBI meme in the US whenever someone talks about loli. It’s just that instead of the FBI, we get the Yakuza.
Never let anyone step on your dreams. You already said that you aren’t seeking to break the law and are not harming anyone, and that’s what matters. If despite this you end up with legal or other troubles, use them to make yourself famous! As PT Barnum might put it, “All publicity is good publicity, as long as they spell your name right”.
Art isn’t about safety. It never has been and never will be. Art is about pushing the boundaries. Your passion for a currently controversial subject matter is a wonderful gift that enables you to do just that.