Marital Arts
Series: Ranma
Sex factor: high
Kink factor: General Weirdness (this is Ranma after all), incest, group sex, domination, double-ended dildo, anal, mild bondage,
BFT: brief pain'n'tears
Long story in which the Saotome and Tendo wives are passing on a secret School of Marital Arts. (Also features a separate Ranko as Ranma's twin sister. And they're *both* cursed.) The wild sex doesn't start until the second file but once it gets going, watch out...