any manhwa that has a sadist/masochist couple in school?

(I think they are in college in this one)
http://www.mangago.me/read-manga/my_partner_s_tastes_and_fetishes/
(Also in college but more fluff less kink)
http://www.mangago.me/read-manga/make_me_bark/?0Ywx
(This one is a manga not a manhwa but they are in highschool)
http://www.mangago.me/read-manga/simplified_pervert_romance/?QCoz
(This one is same as the previous)
http://www.mangago.me/read-manga/sneaky_red/

caste heaven has some in it but idk if its still updating tho...