Rape play is just what EN like the most out of jp's huge library of porn, that's why it's the most localized. Even back in the beta tape era, majority of english porns was rape play (and incest), complete with the infamous porn level acting and terrible music.
Having been in the porn section of Japanese bookstores many times, and gone through a lot back in the day, I can say that the percentages are at least equal.
any tabkoubon of basic-ass porn has a 40% chance of having a chapter of illegal acts of various types.
Japan has multiple hit book, comic and television shows of sweet home Alabama, keep the best genes in the family stuff,and even more “step” or adopted or other “almost” crap.
Minefield of cursed content when I open the Pixiv apps if I don’t go right to my feeds. Most drawing streams are of some weird, raunchy nonsense so I gtfo of there.