[Umihara Minato] Significance of Existence (ENG) =Torwyn=
A swimming prodigy gets injured during practice and finds out her days as a swimmer are over. She decides that her only course of action, obviously, is to stay on the swim team by becoming a sex slave for the boys and the coach. I don’t say this often, but this may be a case where a girl is dumb enough to actually deserve the terrible things that happen in these stories.
Most of the mangaka series relates to gang bang and rape, you really can't make much of a story from either of those aside from NTR. Pretty hot one shot imo.