Spermaniax - Sekisaba! ~Shiritsu Sekigahara Gakuen Joshi Survival Game Bu~

This is SperManiaX’s first game. Yuuichi is starting first year at Sekigahara Gakuen, a school that is famous for having many clubs. But he has absolutely no interest in joining any clubs of them; he had chosen to attend this school only because it was close to home. His osananajimi Sonoka on the other hand desperately wanted him to join a club with her. While looking for Sonoka one day, he was suddenly taken down by people dressed in camouflage with face masks and guns. They demanded him to join their club at gunpoint.