Attack Girls' Swim Team Versus the Undead (2007)

Aki (Sasa Handa) is a new student who joins the girls' swim team and quickly begins to bond with fellow swimmer Sayaka (Yuria Hidaka) in the Japanese action-horror flick Attack Girls' Swim Team Versus the Undead (2007). The two girls get topless and go lesbo on each other after spotting matching birthmarks on each other in the shower that lead them to believe they are sisters. Meanwhile, a killer virus begins turning the students and teachers at the school into homicidal maniacs, leading to blood and guts galore. Nudity, violence, and lesbian sisters—this is going swimmingly!