"Non mainstream"
There's upskirt shots of children in Miyazaki films.
Okay, at the risk of getting a trillion "autistic" rates (like that's ever stopped me), I have to go to bat for this.
Not out of love for Miyazaki but just.... first, what are you calling an "upskirt shot?" Because there's a difference between "the camera is focused so you'll get the best view of her undies" and "you just happen to be able to see them."
And thing is, there was actually a time when "just happening to see them" wasn't even considered that big a deal, or in fact where that or even outright nudity were seen as demonstrating purity/innocence because of how the child absolutely gives no shits.
This standard existed in the west too, as you can see if you've ever seen the old Little Lulu or Little Audrey short cartoons or an episode of Rainbow Brite.
Actually, a memory I have demonstrates the changing standards... when I was like five and watching Rainbow Brite with my sister, she at one point freaked out thinking it just showed Rainbow's bare ass.... we had to rewind the tape and I said "she's wearing underwear, you idiot!" And suddenly that made it okay.
Same deal for Japan.... used to be the idea was "if its a child, it isn't sexual," which is how you get it in shows meant for kids like Yadamon, Doraemon, or even
The Flying House (a show specifically made for
Christians).
It took Japan awhile but eventually they figured out (thanks to the internet, I imagine) that people were watching these shows/scenes for the wrong reasons.... so now you have a binary: shows legit meant for kids like Doraemon or Detective Conan will largely edit these things out or avoid them, but then you get stuff like Kodomo no Jikan which is clearly trying to be appealing "in that way." It's impossible to watch its ending credits sequence and
not feel dirty.