Yamaguchi

"It's Professor Yamaguchi!! He's super strict about the rules!!"

- Nagatoro on Professor Yamaguchi

Yamaguchi (山口) is a background character of the Don't Toy With Me, Miss Nagatoro manga series. He is a well-known professor at Kazehaya High School, very feared by all of its students due to how strict he is regarding the rules.

His first name is currently unknown.

Appearance
Yamaguchi is an extremely tall, thin, gangling, and angularly-built middle age man with short straight black hair with bangs pinned to both sides of his face. He has a very pale complexion, an aquiline nose, and hollow cheekbones. Yamaguchi is short-sighted and always wears a pair of horn-rimmed glasses that obscure his eyes. Despite his skinny and bony physical form, he came off as an imposing and intimidating figure to Kazehaya's students.

He's always dressed in a sober dark suit and tie.

Personality
Yamaguchi seems to be a very stoic, no-nonsense and stern professor, widely known to be extremely strict regarding the school's rules and thus arousing fear in all of his students, including Nagatoro.

Early life
Yamaguchi was born in, , where he became a teacher and started to work as a professor at Kazehaya High School getting the reputation of being extremely strict regarding the rules.

Christmas
On Christmas Eve, Yamaguchi patrolled the building in order to ensure that all the students had left the institute as imposed by the school's broadcast; however, wanting to remain at school a little longer in order to find the right moment to exchange their Christmas gifts, Nagatoro and Senpai escaped him, hiding first in the nurse's office and then on the rooftop, getting interrupted both times by some setbacks.

Manga

 * Chapter 70

Season 2

 * Episode 6

Trivia

 * His last name is and is composed by the kanji "mountain" (山) and "mouth" (口), thus being literally translatable "mountain entrance/gateway".
 * Given that he seem to tower over Senpai (176 cm) his height could be estimated as approximately 180 cm, which is huge for a Japanese man.
 * Ironically, despite being feared for how strict he is regarding the rules, in Chapter 70 while he was patrolling the school, several serious violations of the school protocol occur, remaining all completely unnoticed by him:
 * Couples can be seen almost everywhere in the corridors and on the rooftop.
 * A student (Sakura) makes out with another one on the nurse's office bed.
 * A girl (the President) walks around the corridors and then a club room completely naked.
 * Yamaguchi has a mute role both in the manga and in the anime.