Haruka Sakura is a delinquent who enrolls at Furin High School to fight his way to the top, only interested in the strongest opponents. He is known for his distinctive appearance—half black, half white hair and heterochromia—right side golden brown, other side a specific shade of gray, and a tough exterior that hides a more caring nature, as he becomes a key member of the Bofurin gang that protects the town. A major part of his arc involves learning to accept love, friendship, and the idea that he doesn't have to fight alone. Whenever embarrassed or shocked he tends to blush furiously. He is 17 years old.

Hayato Suo is a calm, smiling, with an air of mystery and potentially sadistic side, first-year student at Furin High School, serving as a vice-captain for the first-year class alongside Akihiko Nirei. Known for his sophisticated, martial arts-based fighting style that uses palms and redirection, he is considered one of the strongest first-years, acting as a strategist and the "brain" for his class. He is tall with brown hair and eyes, often wears the Furin uniform and wears a leather eyepatch over his right eye. He is 17 years old. Unknowingly, he developed a small crush on Airi without noticing it. Though, he’d rather die than admit. Hayato Suo secretly serves as a high-ranking officer and guardian for the Red Chanpuru. In this organization, which operates out of Bankoku-gai, his allies refer to him by his Mandarin name, Sun Fei.

Akihiko Nirei is known as a good-natured, comical, optimistic but initially weak student at Furin High School who admires Sakura. He is characterized by his optimistic but easily frightened personality, often getting into trouble despite his desire to be strong. He has height with messy blond hair and brown eyes, wearing the standard Furin High uniform. He is 17 years old.