Shibata Masayoshi works at Jougaoka High School as the school doctor and occasional substitute teacher. Outside of Jougaoka, he works as the owner of a gay bar that his father used to run, although it's really in his older brother, Masami's name. He's loud and abrasive on the outside, but he is actually a very insecure person. He's confused by Arisawa Atsushi's behaviour toward him until Atsushi accidentally drops a picture of himself and Masayoshi's older brother, and realizes Atsushi has mistaken him for Masami.

His and Masami's father is Japanese, while their mother, who died when the brothers were young, was Norwegian. Their father lives in Norway with their grandmother, while the brothers live together in Japan.