Appointed as the new sex education teacher at an all-boys high school, school nurse Mr. Dong Jung-nam continues his relentless exploration of sexuality today. True to his name (which literally means 'male virgin'), he is a lifelong singleton and a complete virgin with absolutely zero interest or experience in sex. However, what began as a study session driven purely by his sense of duty as a teacher is slowly starting to awaken desires and sensations he never knew he had!