Mr. Yamashiro is a teacher at Third Street School and a minor, recurring character in Recess. It is not stated which grade he teaches. He has a lime green convertible car and practically lives in the teachers' lounge. In which, the butler knows his needs. Miss Lemon sometimes accompanies him socially. He made his first appearance in the episode "Teacher's Lounge, in which he played a prominent speaking role. Since which he made background appearances in the series. He was also seen throughout the 2001 feature-length film "Recess: School's Out"; however, his one speaking role was in the corridor at the start with Coach Kluge.
Friends: Miss Finster, Principal Prickly, Miss Grotke, Miss Lemon, TJ Detweiler, Vince LaSSao, Ashley Spinelli, Grethen Grundler, Mikey Blumberg, Gus Griswald, Randall Weems and Menlo
Enemies: Earwin Lawson, Conrad Mundy, Greg Skeens, Chucko Kowalski, Jocko, Buster, Cheay, Koreo and Kurst the Worst
Likes: Working for Miss Lemon and being in the teachers' lounge
Dislikes: Troublemakers, misbehaving children, falling out with Miss Lemon, and students getting him arrested and troublemakers (especially Lawson) breaking into the teachers' lounge
He is of Japanese heritage, hence his appearance and surname.