Nana Mix!

A girl named Nanami moves to St. Marivel High School from the United States in search of her childhood friend, Kotaro. The school has a student gender ratio of one male to twenty females. She gets into a dispute with a male student nearly twice her size. As she prepares to confront him, she spots Kotaro and hesitates, letting the male student seize her. The situation leaves her struggling to find a way out.