Die Unschuld des Lehrers 01

Math teacher Mamiya Nagisa is teased by his horny students at an all-boys high school on a daily basis. One day genius high school student, Sakura Minato, transfers from America. Minato jumps in to save Nagisa who is teased by the students, but is told, "I want to sleep with you." When he asks senior teacher Tsukioka for advice, he is attacked by him. What will become of Nagisa's purity?