Saishuu Kyoushi(1981)

Emperor High School seems to not care anymore about education, letting their students have free rein over nearly everything. The president even had to resort to teachers who came right out of a prison, because the students were so violent. One day, Ganpachi, a self declared teacher arrives, intending to bring order to this high school by introducing fear into the leader of all the gangs, Hinako. Having a hard time standing up against him, she still believes in the power of her lucky kitty gym pants.

As it turns out Ganpachi ran away from a genetic laboratory, which is probably why he has the tenacity and behavior of a cockroach.