Full name: Reiji Kumashiro. A new teacher and former biker gang leader. He has a foul mouth, loves women, and seems irresponsible, but he's a hot-blooded man who never abandons a student. He's a strong fighter and the first to dive in when trouble arises. His un-teacher-like attire and attitude make him a target of criticism from those around him. His catchphrase is "Don't run away from life."

A cool, top-of-the-class student. She doesn't trust others and keeps her emotions hidden. Raised in a strict household, she always carries her burdens alone. She slowly begins to show her true feelings only to Reiji.

A bright and popular gyu-style girl. She's famous on social media but suffers from online harassment behind the scenes. She's good at reading the room and often forces a smile. She loves romantic gossip and often drags those around her into her antics.

The strongest delinquent in school. He hates teachers and won't open up to anyone. Though he's always fighting, he cares deeply for his friends. He begins to change through repeated clashes with Reiji.

A serious and strict female teacher. She views Reiji's educational methods as dangerous. However, she acknowledges his genuine commitment to protecting the students. She's scary when angry, but she's actually quite caring.