Fudanshi Sensei!!!!! is a rom-com about an otaku high school teacher and his relationship with one of his students. The story begins with biology teacher Kazuto Kiryu visiting the club of Ageha Saotome, who actually sells BL doujinshi! Mr Kiryu gets a lot of attention from the female students for being a cool teacher, but he is actually a fudanshi!

(Source: Manga Tokyo)