south korea is weirder tbh
sorta not sorta
as a person with dual citizenship (us and japan) I feel inclined to answer that society in Japan is literal hell; nobody will date you after college, everybody just moves on with life and has a small social circle of friends mostly of the same gender, etc etc. When I was going to school there I noticed one thing- when things came to things, all the girls would flock to their groups and all the guys would be in their own groups. There's no "mingling" amongst other genders, just with the same gender and it's more of a conformist society, so nobody speaks out about how wrong it is, etc etc. It contributes to conversations about love not being awkward (because we're all pervy little 6th graders) and people expressing their loveuality in weird ways. It's almost sort of like security and out of date technology there, they have loving core 2 duo desktops running a version of XP (please note I went to a school in a town that's in the middle of buttforget nowhere), etc etc. Honestly, it's a large amount of factors contributing to it- schooling, social conditions, media pressure about how the internet is evil and nobody should use it, blah blah that lead to these sort of lewd products being made.
I'm definitely wrong on somethings, have Akio give you more detail or whatever