Kojiro is a character in the Nekomajin series. He was originally a small skinny boy, but later became a short, fat teacher working at Nekoshima School.
Kojiro is generally underconfident, and he can not control his students. He asks Neko Majin Mike to replace him for one day at school, because he has to sell Nekomatsutake mushrooms to the Dog Dragon Gang.
Kojiro soon becomes overconfident, only to be quickly reminded of his weak strength when he is beaten by Pochimura of the Dog Dragon Gang. Once again, Neko Majin Mike helps him, this time by taking control of his body and defeating Pochimura.