Masahiro Hashimoto is the new percussion instructor for the Kitauji Concert Band, hired by Noboru Taki, his then college classmate, to help with the band on their path to the national band competition. He is an alumni of Kitauji High School.

Hashimoto is fun-loving, athletic, and humorous, and is consequently highly popular with his percussion students. He has also repeatedly offered to share details with students concerning Taki's wayward misbehaviors in college.