The story behind Collector is that the main character has attended a well-reputed high school for a long time. Yet, the main character was disgust by their strict school policy and the boredom in the school. He wanted something interesting besides attending school and go home. And thus, the main character participated in a strange club that his friend has introduced to him. In this club, the main goal is to seduce girls to the clubhouse and rape them! And guess what? The main character is assigned as the person who will be responsible to bring the girls to the clubhouse. From here on, your quest of hunting down girls begins.

[From Anime Densetsu]