Yamamoto

Yamamoto is a teacher that shared the classroom with Ryōko Tamiya.

Appearance
Yamamoto is a tall middle-aged man, with shoulder-length black hair and brown eyes. Being a teacher he is seen wearing business attire to look professional.

In the manga he wears glasses.

Personality
In the manga, Yamamoto demanded that his class pay attention to his teaching. He hit Shinichi in the head for embarrassing him in front of the class. He does seem to care for his students as he made sure they stayed in line and evacuated safely during the parasite attacks. He was able to keep his composure while other teachers, most notably Sasaki, were frantic and screaming.

Plot
In the manga, Yamamoto is first seen instructing his class. He quickly notices Shinichi chatting with other students and proceeds to throw a piece of chalk at him. Without looking or noticing, Shinichi—or most likely Migi—catches and crushes the piece of chalk. Embarrassed, Yamamoto hits Shinichi on the back of the head, confusing the boy.

The next day, Yamamoto, who is still hung up on Shinichi's antics, throws another piece of chalk at him. This time it hits Shinichi in the head. Yamamoto quickly apologizes and goes back to teaching the class.

In the anime, he is first seen taking Shinichi's phone in class with an amused look on his face.

Yamamoto is mentioned during an assembly in the gym after Ryōko's introduction. It's said that she'll be the assistant teacher.

Much later, while he is teaching class Shinichi begins yelling and soon leaves the class room, confusing him and prompting him to demand an answer. During Hideo Shimada's rampage he kept a calm demeanor when escorting his class to safety. When Shinichi begins acting strangely and tries to separate himself from the class, he notices this and slaps the boy across the face, ensuring he stays with the class.

Later in the anime, Yamamoto replaces another unnamed teacher from the manga, where he calls on Shinichi in class to read and catches him daydreaming. He sarcastically tells Shinichi to leave if he doesn't want to be here. He along with the class are stunned when Shinichi actually leaves.

Abilities
It's said that he can throw a piece of chalk with the precision and power of a professional pitcher. He uses this as a disciplinary tactic on students who aren't paying attention. He was seen doing this twice, failing the first time, but connecting the second. The class seems to be well aware of this and find it quite humorous.