Bokura no Kankin Shinsatsushitsu ~Shimai Torikaekko Choukyou~

The protagonist, Hasumi Yuuto, is a high school student who, while his parents, who work as obstetricians, are away from home, plots with his best friend, Daiki, to swap their sisters, Ai and Misaki, and begin a rape game in the examination room.
Betrayed by their own families and sacrificed for a sexually insane game, what fate awaits Ai and Misaki...?!