Mushitsukai

Main character is a descendant of samurai clan. He does research on insects at school. One day he receives a request from club deputy chairman to bring mysterious newcomer Miyaka in. Protagonist accepts, because he feels this mission has distinctive links to his past ancestry. Miyaka is surrounded by elite invincible female squad all the time. In order to defeat them and approach Miyaka protagonist develops insects that act like pheromones on women. His sexual assault begins.