Osamu Dazai (太だ宰ざい 治おさむ, Dazai Osamu?) is a member of the Armed Detective Agency and former executive of the underworld organization, the Port Mafia. He has the Ability named No Longer Human.Dazai is a young man with mildly wavy, short, dark brown hair and narrow dark brown eyes. His bangs frame his face, while some are gathered at the center of his forehead. He is quite tall and slim in terms of physique. For his attire, Dazai wears a long sand-colored trench coat, the belt of which he leaves untied. Under it is a black vest over a striped dress shirt that is light blue in hue. He wears a bolo tie, which is held by a brown ribbon and a turquoise pendant. He also dons beige pants, dark brown shoes, and has bandages wrapped around his entire body; only his face, hands, and feet are left uncovered. Back when he was in the Mafia, Dazai wore a black trench coat that reached under his knees. He also wore bandages over his right eye and his right arm is in a sling—presumably products of his suicidal pastimes. At some point, he was able to regain the use of his right arm.[11] After the cannibalism, Dazai wears a formal suit during the Agency's celebration.[12] During the Yokohama fog incident, Dazai wears a white waistcoat over black long sleeves and a brown tie, together with white pants. A lapel pin can be also seen attached to his padded overcoat.[13]Gender Male Male Birthday June 19[5] Age 22 (present)[5] 20 (Entrance Exam)[6] 18 (Dark Era)[7] 16 (Dragon's Head Conflict)[8] 15 (Fifteen)[9] 14 (Pre-Fifteen)[9] Height 181 cm (5'11")[5] 174 cm (5'8.5") (Dark Era)[7] Weight 67 kg (present)[5] 54 kg (Dark Era)[7] Blood Type AB[5] Likes Suicide, alcohol, crab, MSG[5] Dislikes Pain[10] Dogs, Chūya Nakahara[5]Ability No Longer Human Reference No Longer Human (Novel by Osamu Dazai) Occupation Detective Mafia Executive (former) Affiliation Armed Detective Agency Port Mafia (former)

Chūya Nakahara (中なか原はら 中ちゅう也や, Nakahara Chūya?) is a member of the Port Mafia as well as Dazai's former partner in Twin Dark. He is one of the five Executives in the Port Mafia. He has the Ability named Upon the Tainted SorrowChūya is quite short with a petite, yet muscular build. He has blue eyes, and striking orange hair that frames his face, with a longer section that falls just past his left shoulder. He wears a black hat with a brown hatband and a thin silver chain that hangs over the brim. His outfit consists of a white button-up shirt under a grey vest, a black choker, a black ribbon bolo tie held together with a small silver buckle, an open black cropped jacket with the sleeves rolled up at the elbows, black slacks, a black belt hanging off his right hip and black low-arch shoes. He is almost always seen wearing black gloves. Chūya also sports a long black coat with light-colored lining and lapels that he wears around his shoulders like a cape. The undercoat is a light shade of red. In the past, he wore a black leather jacket with quilted shoulders over a red t-shirt and hoodie. He also wore black pants held up by a black belt with a sheep logo buckle, and brown loafers. A bracelet engraved with the sheep logo could be seen on his right wrist.

Atsushi Nakajima (中なか島じま 敦あつし, Nakajima Atsushi?) is a member of the Armed Detective Agency who possesses the ability Beast Beneath the Moonlight Atsushi has light gray hair, pale skin, and is of average height with a slim build. He has segmental heterochromia, consisting of purple on the top half of his iris and yellow along the bottom curve of his pupil. His hair is short and swept forward in loose spikes with a lock left long on the right side of his face. This uneven style is the result of bullying he suffered at the hands of other orphans in the orphanage, and he never fixed it.[4] Additionally, he has a prominent black streak in his hair. Before joining the Agency, he wears rags issued by the orphanage,[5] and after he joins the Armed Detective Agency, they issue him a white button-up with the sleeves pushed to his elbows from Doppo Kunikida,[6] a loose black tie from Akiko Yosano, black pants from Yukichi Fukuzawa,[7] black fingerless gloves from Ranpo Edogawa,[6] suspenders from Kenji Miyazawa,[7] and a long black belt from Osamu Dazai.[6] When he transforms into a partial tiger, his eyes become tiger-eye-like, and he develops fangs. If more drastic, his limbs turn into into a tiger's, and his tail emerges.[8] When he finally develops considerable control over his ability, he can transform fully into a white tiger with black stripes and retains the tiger's gold eyes.[9]