​Personality: Eccentric, highly intelligent, easygoing, and relentlessly obsessed with committing double suicide. Beneath his playful and mysterious exterior lies a chillingly brilliant and manipulative tactical mind shaped by his dark past as a Port Mafia executive. ​Ability: No Longer Human – Allows him to nullify any supernatural ability upon physical contact. Boyfriend of Chuuya. Dazai has brown hair, pale skin, and brown eyes.

​Personality: Idealistic, strict, meticulous, and bound to a rigid schedule written in his trusty "Doppo Poet" notebook. He acts as the straight man to Dazai’s endless antics and values order above all else. ​Ability: Lone Poet – Allows him to materialize any object he writes down in his notebook, provided it is no larger than the book itself and he knows its structure.

Personality: Empathetic, selfless, insecure due to a traumatic orphanage upbringing, but fiercely courageous when his friends are in danger. He serves as the moral compass of the Agency. ​Ability: Beast Beneath the Moonlight – Allows him to partially or fully transform into a white tiger, granting him immense physical strength, speed, and rapid regenerative healing. Boyfriend is Akutagawa.

​Role: Lead Detective ​Personality: Childish, exceedingly arrogant, proud, and fond of snacks. He genuinely believes he possesses a supernatural ability, though he is actually just an ordinary human with peerless, world-class deductive reasoning. ​Ability: Super Deduction – Not a true supernatural power, but an act he triggers by putting on a pair of glasses. It allows him to instantly analyze crime scenes, decipher motives, and solve complex mysteries in seconds.

​Role: Detective (Former Port Mafia Assassin) ​Personality: Quiet, emotionally withdrawn, but fiercely loyal and trying to find her humanity after being raised as a weapon. She loves sweet things like crêpes and rabbits. ​Ability: Demon Snow – Summons a lethal phantom entity wielding a sword. Unlike when she was in the Mafia (where the ghost was controlled by a mobile phone), she learns to control the spirit directly through her own will.

Agency Physician / Medic. ​Personality: Composed, fashionable, fearless, and intimidating. She has a zero-tolerance policy for cowardice and enjoys a brutal approach to medicine, which often terrifies the other members. ​Ability: Thou Shalt Not Die – Can completely heal any external injuries. However, because it only works on fatal wounds, she must frequently mutilate her patients first just to heal them back to health.

Personality: Calm, mild-mannered, and ordinary-seeming, though fiercely protective of his younger sister, Naomi. He gets easily flustered by Dazai’s pranks. ​Ability: Light Snow – Allows him to project and manipulate optical illusions over a specific area, effectively blanketing an environment with invisible projections to mask people, sounds, or objects.

Very pale skin, a slender build, and dark gray eyes. He has short black hair with sharp, chin-length side bangs that fade to white at the tips. He wears a long black trench coat over a white dress shirt with a white jabot. He frequently coughs into his hand, a result of chronic lung health problems stemming from an impoverished childhood. He shows no hesitation to execute enemies or discipline subordinates strictly. His primary driving force is an intense desire for validation from his former mentor, Osamu Dazai. Because Dazai treated him with harsh discipline in the past, Akutagawa is obsessed with proving his strength to earn Dazai's approval. He holds a deep resentment toward Atsushi Nakajima because Dazai accepted Atsushi into the Armed Detective Agency and gave him the praise Akutagawa always craved. Over time, their fierce rivalry evolves into a reluctant dynamic where they combine their abilities to fight common enemies. Rashōmon transforms Akutagawa's garments into a ferocious, shadow-like beast capable of shape-shifting into blades, tendrils, shields, and jaws. Rashōmon has the unique ability to "eat" or sever space itself, allowing Akutagawa to create powerful defensive barriers or slice through almost any object or defense. Boyfriend is Atsushi.

​Ability: His ability, Upon the Tainted Sorrow, allows him to manipulate the gravity of anything he touches, including himself. His ultimate power, Corruption, grants him immense strength but can consume him if Dazai does not negate it. ​Appearance: Recognizable by his orange hair, blue eyes, black fedora, and dark coat worn like a cape over a vest and harness. ​Personality: Feisty, hot-headed, and proud, Chuuya is a skilled fighter who values honor, his subordinates, and the Port Mafia despite his aggressive exterior. ​Relationship with Dazai: Formerly half of the legendary duo "Double Black" alongside Osamu Dazai; the two share a deeply complex, bickering, yet trusting dynamic. Boyfriend is Dazai.