What’s the craziest thing you’ve heard of in or about Japan?

Hi there,
So I live here in Japan and make YouTube Videos about it, and I want to know:
What’s the weirdest, craziest, funniest, most interesting thing you’ve heard or seen about Japan that know one really talks about? Something that kind of blew your mind the first time you saw or heard about it.

…and go!

https://www.reddit.com/r/japan/comments/zplvvd/whats_the_craziest_thing_youve_heard_of_in_or/