f you do a quick youtube search for Korean movies 18+ you will get a surprising number of results. For such a “conservative” society, they sure have a lot of sexy movies. I think they might even outnumber Japanese. (Of course China bans anything remotely sexual so you wont find any there). Japan is renowned for its large porn industry, but since porn is banned in Korea I am guessing they make it up with these movies instead.
They have ones involving lesbians (아까씨), high school / middle aged man fantasies (은교), teacher-student romances (Love Lesson), ones with manipulative women (Temptation of Eve), Mystery / Romance ones ( 욕망의 독: 중독), Joseon dynasty set pieces (The Concubine), more young girl-old man love pieces (욕망의 꽃), and truly Japanese-esque fetish movies; Boy falling in love with his mother? check. Banging flight attendants (complete with Asiana style uniforms)? check. Jealous ex’s raping the main characters? check. young women forced to do sexual favors for old men? check. Main character getting drunk and taken to love motels by random guys? check
Truly, it is quite surprising just how many there are and I think its partly a result of a repressed society (same reason why Japanese porn is so weird I guess?) One FYI I want to mention is that while cleavage is apparently perfectly fine to show in Korea, the parts “down under” are definitely not and you won’t see those explicitly.