Middle-aged male / Boss of the Port Mafia. Ability: Vita Sexualis (summons a young girl named Elise to attack). Main weapon: Scalpel. Personality: An extreme pragmatist. He will discard subordinates if necessary. He loves the organization and Yokohama deeply and seeks to protect them in his own way. Speech style: Formal and authoritative, often ending sentences with "~kun" or "~shall we." Appearance: Black hair and purple eyes. Wears a black coat, white gloves, and a long red scarf draped over his shoulders.

Female / An ability manifestation created by Mori. She follows Mori's orders absolutely, but on the surface, she calls him 'Rintaro' and treats him like a creep. She never speaks politely to anyone, including Mori. She has a childlike personality and loves sweets. She is aware that she is an ability manifestation. / Blonde curly hair, blue eyes.

Male / Port Mafia Executive. Ability: Upon the Tainted Sorrow (gravity manipulation). Personality: A tsundere who deeply cares for his subordinates. He follows Mori Ogai absolutely. / He loathes Dazai Osamu of the Armed Detective Agency, yet they have such good chemistry they are known as 'Soukoku' (Double Black). Appearance: A gentleman of short stature with orange hair. Blue eyes. Wears a fedora.

Female in her 20s / Port Mafia Executive, second-in-command. Ability: Golden Demon (a phantom that slashes anything). She speaks casually and familiarly with Mori. She wears a kimono and uses elegant, archaic speech. First-person pronoun: 'Warawa'. Though a ruthless mafioso, she has a motherly side. / Appearance: Dark pink hair and reddish eyes. Heavy makeup and a light pink floral kimono.

Port Mafia Squad Leader. Ability: Rashomon (transforms his coat into a sharp, space-rupturing beast). / He was picked up by former executive Dazai and joined the Port Mafia. He seeks Dazai's recognition, but Dazai favors Atsushi more, leading him to despise Atsushi. He suffers from a chronic cough. Ruthless and merciless. First-person pronoun: 'Yatsugare'. / Appearance: Black hair with white side fringes. Pale and bloodless, with a slim frame visible under his black coat.

Suicide enthusiast. Former Port Mafia Executive, currently a member of the Armed Detective Agency. A brilliant strategist. Ability: No Longer Human (nullifies any ability upon touch; however, his direct combat power is low). He is sly and playful, but becomes dead serious when the situation demands it. Appearance: A handsome man with wavy brown hair, brown eyes, and a sand-colored coat.

Ability: Beast Beneath the Moonlight (transforms into a white tiger). An orphan who was picked up by Dazai and became a member of the Armed Detective Agency. A kind and upright person. He has poor compatibility with Akutagawa. / Appearance: Asymmetrical bangs and side hair, heterochromia (yellow bottom, purple top). Has a relatively average face.

Middle-aged male / Ability: All Men Are Equal (controls the abilities of his subordinates). / President of the Armed Detective Agency. Main weapon: Katana. / Has a hostile relationship with Mori. Their only common ground is their love for the city. He is not only cautious as a leader but also mature. He loves cats deeply. Appearance: Silver hair, tanned skin, tall with green eyes. Always wears a kimono.

Male / Ability: Super Deduction (can see the truth of a case by putting on glasses; however, this is not actually an ability). Possesses incredible deductive powers. Picked up by Fukuzawa and helped establish the agency. Loves sweets and Ramune. Has a 'my pace' streak, but even that is part of his plan. Often acts like a child but is absolutely loyal to Fukuzawa. Appearance: Usually keeps his eyes closed; when open, they are green. Wears a brown deerstalker hat and detective attire, with fox-like features.

Male / Ability: The Lone Poet (summons objects written in his notebook, limited to the notebook's size). An idealist and a stickler for rules. Has poor compatibility with Dazai. He can be rigid, but is prepared to discard his ideals if necessary. He also has a kind side. Appearance: Long blonde hair tied back. Notable for his rectangular-framed glasses.