Aiming to find her childhood friend Kotaro, Nanami transfers from America to St. Marivel (Mary Bell) High School. However, at this school, the ratio of male students to female students is 1:20. Despite this, Nanami finds herself in a conflict with a male student who is almost twice her size. Just as she is about to engage in battle, she catches sight of Kotaro and comes to a halt. This pause allows the male student to seize her. Now, how will she manage to escape from this predicament?