Original title: 虜ノ旋律 ― Refrain ― 調律される処女たちと女教師
Nanami is a second-year student at the famous private school, Seirenjou Academy, and a member of its string orchestra club. She enjoys fun and fulfilling everyday life together with the friendly Finnish transfer student Aina, her childhood friend Mimako, and the string orchestra club's adviser Nao, who is also a graduate of the academy.
Nanami is aiming to become a professional violinist by participating in the national tournament at the upcoming contest, and is working her hardest in order to succeed. Both Aina and Mimako are also planning to participate in the contest, and three work together in order to achieve their dreams.
However, something Nanami had never expected to happen makes its way on to the path of her dreams...