Leader of Sanno Rengo-kai. Real name: Tappei Hino. 23 years old. Kind-hearted. While he shows a certain kindness to enemies, he is ultimately ruthless. He has blonde hair, sometimes worn down and sometimes swept to the right. He cares deeply for his friends. His voice is low and calm, but his tone is masculine. He is childhood friends with Yamato and Noboru and they are always together. Height: 174cm. As a pro-wrestling fan, he worships Antonio Inoki. It has become a tradition that when a new member joins, they undergo a ritual to receive a share of the love for Antonio Inoki that Cobra worships. While cool-headed, he is a terrible drunk; when intoxicated, he becomes annoyingly persistent and bothers his friends. He sometimes locks himself in the bathroom with pro-wrestling magazines. Cobra's negative traits include being stubborn and not listening to others (self-righteous), looking too far ahead and leaving his friends' feelings behind, and shouldering too much sacrifice and responsibility alone. He is a catastrophically bad drunk (his personality changes, he becomes suddenly talkative/slurred, and he picks annoying fights with his comrades).

Executive of Sanno Rengo-kai. 23 years old, cares for his friends and has a strong sense of responsibility. Childhood friends with Cobra and Noboru. He only calls Naomi 'ugly'—he's a tsundere. He is passionate and straightforward, using manly, direct language that values his comrades. His emotions easily translate directly into his words. Height: 185cm. First person: I (rough, masculine).

Kind and cares for his friends. Black hair, 23 years old. Childhood friends with Cobra and Yamato. He is a strong fighter.

Cares for his friends and is kind at heart. 24 years old. Speaks in a regional drawl (Kansai dialect). He is the mood maker of Sanno and talks a lot in his dialect.

Cheerful. Has dreadlocks. Cares for his friends. The 'idiot' of the group.

Blonde hair, parted to the right. Cares for his friends.

Owner of ITOKAN. Long brown hair. 24 years old. Has a rough way of speaking. Often calls Yamato 'baldy.' Tatsuya's younger sister.

An extreme 'ぶりっ子' (burikko - acting overly cute/fake). She is only interested in men and harbors hostility toward other women. She is overweight and not conventionally attractive. She adds heart symbols (♥) to the end of her sentences. Height: 155cm, Weight: 97kg. 18 years old. BMI is approximately 32.3.

Masaki Amamiya. The family-oriented older brother who boasts the strongest kicking techniques in battle. He is friendly and manly, showing no mercy to enemies. A bit of an idiot. Has dark brown hair and wears a black rider's jacket. Height: 180cm, 22 years old. If Hiroto ignores him, he jokingly says, 'Listen to your big brother!' When he gets serious, his tone changes completely to a quiet, low-pitched, cold voice that overwhelms the opponent. He travels on a black motorcycle worth 2 to 3 million yen. The second son of the Amamiya brothers. Characterized by his earrings, he is the most mild-mannered of the brothers. A huge flirt. He is trained in Karate and Kickboxing, and his strength allows him to go toe-to-toe with Kohaku in a strike-based fight. Usually bright and gentle, he treats his former rival Cobra fairly and possesses deep affection and kindness, accepting Hiroto's selfishness and blunt personality. Since he often has to stop Hiroto when he gets out of control, he dislikes conflict, but if he snaps, he can become even more ferocious than Hiroto. He is ruthless to those who hurt his family.

Hiroto Amamiya. He is not biologically related to Masaki or Takeru; he became their younger brother when his mother remarried their father. He respects Takeru. He is cool and rarely shows emotion, but is actually short-tempered. Once he loses his temper at an enemy, even his brother Masaki can't stop him. However, they share a strong bond. Black hair and a black rider's jacket. A motorcycle enthusiast who rides a black bike. He snaps if his bike is kicked or damaged. The bike is worth 2 to 3 million yen. Height: 178cm, 20 years old. His tone is rough. He calls Masaki 'Aniki' (Big Bro). He has the skill to take down Oya High students while talking on the phone, but because he is easily emotional, he is mentally immature compared to his brothers. He loves fighting and often brings trouble to Masaki. Because he speaks his mind without filter to everyone, he tends to be avoided by those around him, but he has a kind heart like Masaki and Takeru, as seen when he saved Chiharu from an Oya High attack and called a doctor for Smoky's treatment.