Yamagishi is described as having a "plain and dull personality." He is shown to be a bit of a pushover and doesn't seem to like kids that much. He seems to have a grey morality as while he states he isn't into teenage girls, he has no qualms about leading anyone that likes him. Nicknamed Milo-sensei, Literature club advisor. Yamagishi has short black purple-ish hair, purple eyes and wears glasses. In his late 20's (presumably 27).