Hitorijime My Hero

Masahiro Setagawa's life as an errand boy for the neighborhood bullies takes a sudden turn when he meets Kousuke Ooshiba, a man notorious for taking down local gangs. A year later, Masahiro and his former friend Kensuke Ooshiba attend high school, where they're surprised to find Kousuke as their math teacher. As they get to know Kousuke better, Masahiro starts to see him as a role model, while Kensuke develops a strong desire to protect him. Kensuke's childhood friend Asaya Hasekura returns, revealing a complicated history with Kensuke.