A megalomaniac with the ambition to take over the world, Tatsuya transferred to a new school. There, he begins to charm and impregnate each and everyone of his classmates (including his teacher) and convincing them to help with taking over the world. The girls in his harem all love him, but has his heart set on Sayaka. However, he does appear to possibly be in love with all of the girls as well, as they are more than content to share Tatsuya, and bear his children.