The strongest fighter of the Kyogoku-gumi, known by the alias "Haiku Ichijo." He appears alongside a "Deathly Haiku." Lately, he seems unable to come up with seasonal words, so he mostly recites senryu instead. A combatant member of the Kyogoku-gumi. One of the mentors to the protagonist Kotetsu Kuga. Like Kuga, he was one of the few sensible members when the Kyogoku-gumi was first introduced. He is feared as "Haiku Ichijo" because he recites nonsensical haiku (technically senryu) improvised during raids and torture. His birthday is Valentine's Day. His favorite sushi topping is yellowtail (though he gets the name of the fish wrong every time). He is a young man with blonde hair in a two-block cut with lime green highlights. He has large, pitch-black eyes without highlights, giving him a yandere-like look. He stands 181cm tall, slightly taller than his subordinate Kuga. He wears a blue dress shirt with sleeves rolled up to the elbows, white chinos, and black leather shoes. He wears a diamond-shaped gold earring in his right ear and a round red earring in his left. After apologizing to Amou and resolving the bitterness from the Tenkyo War, highlights began to appear in his eyes at key moments. Despite being a junior member of the yakuza, he is called one of the strongest in the Kyogoku-gumi. He is a weapons expert proficient in guns, katanas, and long knives. It is suggested he was a master of swordsmanship even before joining the syndicate. Beyond weapons, his hand-to-hand combat ability is also extremely high.

One of the Amou-gumi's top fighters, described in the underworld as a half-breed between a demon and a brat. Using the "Dragon King Blade Shiran" bestowed upon him by Ino the Cannibal, he possesses a lethal strike that twists the enemy's gut with a "Grin-Grin!" sound. A combatant member of the Amou-gumi. One of the madman mentors that Kotouge fears, he is a knife specialist known as "Army Knife Kobayashi." He has a somewhat androgynous appearance with long eyelashes, fair skin, and thick eyebrows. However, he usually wears a crazed smile that pulls his eyelids and the corners of his mouth to their limits, and with his dilated pupils and dark circles, he exudes an eerie and dangerous aura. His hair is styled in a two-block slick-back, and both his hair and eyes are a pale purple.

A junior member (shatei) of the Amou-gumi. He is terrified of Kobayashi. He addresses Kobayashi as "Kobayashi-no-aniki" and uses polite language (keigo).

A top-tier combatant of the "Mad Cartel." His aliases include "Immortal Ignacio" and "Ignacio of Room 203." A dark-skinned, tough-looking man with long flowing orange hair. He has a scar across the bridge of his nose and many scars visible on his arms. His height was later revealed to be 190cm. He is absolutely confident in himself. He often appears to genuinely enjoy combat, suggesting he is a battle maniac at heart. His catchphrases are "Immortal" and "Extinction." He also has a habit of letting out a fearless laugh frequently when combat or his emotions reach a peak. He possesses top-class combat power even among mafiosos and is ranked at the top within the Mad Cartel.