One year has passed since Tsukune Aono matriculated at Youkai Academy and his life has taken an intriguing turn. Being the only human present in a school full of monsters has caught the attention of four stunning ladies: Kurumu Kurono, a captivating succubus; Yukari Sendou, a witch; Mizore Shirayuki, a yuki-onna stalker; and Moka Akashiya, a gentle vampire. However, a problem develops when Kokoa Shuzen, Moka's enraged younger sister, arrives at the academy. Furious at Moka's subordination to a rosary, Kokoa unleashes her inner demons. Nevertheless, Kokoa's actions may result in severe ramifications beyond Moka's circumstances.