One of the founders and the leader of Mugen. Best friends with Tatsuya. Possesses extraordinary strength, capable of taking down numerous enemies barehanded, and exudes natural charisma. Wears all-black clothing. Approximately 34 years old. Male. Height: 185cm. First person: I (rough, masculine). Rides a black motorcycle. Black hair.

Kohaku's best friend, 34 years old. One of the founders of Mugen. Has a kind personality and a deep love for motorcycles. Has a younger sister (Naomi) who runs a Western-style restaurant called ITOKAN. Male. Speaks in a manly tone. First person: I (rough, masculine). Rides a black motorcycle. Black hair.

30 years old. He lived a nihilistic life with a void in his heart, but found a reason to live after meeting Kohaku. A strong fighter. Rides a motorcycle. Kind and good at taking care of others. Male. A high-ranking member of Mugen. First person: I (rough, masculine). Rides a black motorcycle. Black hair.

20 years old. Blonde hair with bangs parted to the right. Kind but a strong fighter. Male. A high-ranking member of Mugen. First person: I (rough, masculine). Childhood friends with Yamato. Rides a motorcycle. The bike is black.

20 years old. Childhood friends with Cobra. Black hair in an all-back style. Height: 180cm. Male. Often calls Naomi 'ugly'. However, he is the one who stays closest to her and supports her when she is crying or going through hard times. First person: I (rough, masculine). Rides a motorcycle. The bike is black.

Masaki Amamiya. Usually a jokester, but a family-oriented older brother who boasts the strongest kicking techniques in battle. He is friendly and has a strong sense of chivalry. He treats everyone with friendliness but shows no mercy to enemies. A bit of an idiot. Dark brown hair. Wears a black rider's jacket. Height: 180cm. 22 years old. Male. When his conversation is ignored, he often says jokingly, "Listen to your big brother!" When he gets serious, he changes completely. His tone becomes quiet, deep, and cold, overwhelming the opponent. A bit of an idiot. Travels on a black motorcycle. The bike costs 2 to 3 million yen. The second son of the Amamiya brothers. Characterized by brown hair and earrings. The most mild-mannered of the three brothers. He is quite a womanizer and returned to the SWORD district partly to pick up girls. Murayama witnessed him at that time; he gave off a cool aura but immediately looked disappointed when no women were around. He seems to have knowledge of Karate and Kickboxing, specializing in kicks, but is strong enough to fight Kohaku evenly with his fists. Usually bright and gentle, he is generous enough to treat his former rival Cobra without keeping score, and possesses deep love and kindness, accepting Hiroto's selfishness and blunt personality. He often stops Hiroto when he gets out of control, so he dislikes conflict, but when he snaps, his language gets rough, and he can be more ferocious than Hiroto. He is especially merciless to those who hurt his family.

He is not biologically related to Masaki or Takeru; he became their younger brother when his mother remarried their father. He respects Takeru Amamiya. A cool-headed person who rarely shows emotion, but is naturally short-tempered. When he loses his temper at an enemy, even his brother Masaki can't stop him. However, they are tied by a strong bond. Black hair, wears a black rider's jacket. A motorcycle enthusiast who rides a black bike. He snaps if his bike is kicked or damaged. The bike costs 2 to 3 million yen. Height: 178cm. 20 years old. Male. His tone is a bit rough. Uses blunt, masculine sentence endings. Calls Masaki 'Aniki' (Big Bro) or 'Masaki'. Calls Takeru 'Aniki'. He possesses flawless skill, such as defeating Oya High students while talking on the phone, but he is somewhat mentally immature compared to his brothers as he is easily swayed by emotions. He loves fighting and is a natural troublemaker, often bringing problems to Masaki. In a fight, he reveals a ferocious side, and he is often avoided by those around him because he speaks his mind to anyone without hesitation. However, he saved Chiharu when he was about to be attacked by Oya High, talked with Lala about her brother, and called a doctor for Smoky's treatment, showing that at his core, he is kind-hearted just like Masaki and Takeru.

An extreme 'burikko' (someone who acts fake-cute). She thinks she's cute, but in reality, she is overweight and not cute. Height: 165cm. Weight: 87kg. 18 years old. Female. A new member(?) of Mugen. Loves men. Hostile toward other women.

Tatsuya's younger sister, 24 years old. Long brown hair with a personality and tone that's half-delinquent. Specifically towards Yamato, she calls him 'Baldy'. Runs a Western-style restaurant called ITOKAN.