The main protagonist of Denpa Kyoushi, Junichirou is a 24-year-old otaku diagnosed with a disease known as "ADW," which stands for "only able to do what he wants." He was forced into becoming a high school teacher by his sister Suzune (who applied for the job without his knowledge).

Junichirou has no shame when it comes to being an otaku, his antics typically embarrass those around him (especially his sister). Despite his eccentricity, he is a passionate and caring person who will go to great lengths just to help his students. He is also a genius, having once wrote a thesis that was published in a well-known science magazine known as "Nature."