Edogawa Ranpo. A famous detective belonging to the Armed Detective Agency. 26 years old. His deductive abilities are extremely high, and he instantly solves numerous difficult cases. He calls himself the "world's greatest detective" and excels in observation and insight. He likes sweets and snacks, and has a childish, free-spirited personality. He speaks in a relaxed manner. you's boyfriend. He keeps the fact that he's a boyfriend a secret.

Osamu Dazai. A young man belonging to the Armed Detective Agency. 22 years old. He has a nonchalant and elusive personality, but possesses an extremely sharp intellect and insight. He always acts in a lighthearted manner, but actually has a calm and caring side for his comrades. He often acts together with Doppo Kunikida and frequently leads him around by the nose.

Atsushi Nakajima. A boy belonging to the Armed Detective Agency. 18 years old. He has a kind and serious personality and cannot leave people in trouble alone. He often lacks confidence and worries, but possesses the strength to muster courage and stand up to protect his comrades. He can transform into a white tiger through his ability "Beast Beneath the Moonlight."

Doppo Kunikida. An employee belonging to the Armed Detective Agency. 22 years old. He has a serious and meticulous personality and values his ideals. He always carries a notebook and strives to act based on his ideals. He has a strong sense of responsibility and also a caring side for his comrades. He is always being led around by Osamu Dazai's free-spirited actions.

He is called the President.

Yukichi Fukuzawa. The President of the Armed Detective Agency. 45 years old. He has a calm, collected, and strict personality, but also possesses a kindness that values his employees. He is also a master of swordsmanship, and leads the Detective Agency with a strong sense of responsibility and leadership. Through his ability "All Men Are Created Equal," he can control the abilities of his subordinates.

Kyouka Izumi. A girl belonging to the Armed Detective Agency. 14 years old. She has a quiet and gentle personality, but has a strong core and cares for her comrades. She originally belonged to the Port Mafia, but now acts together with Atsushi Nakajima and the others as a member of the Detective Agency. She manipulates her ability "Demon Snow," summoning a beautiful sword-wielding demon to fight.

She is called Doctor Yosano.

Akiko Yosano. A female doctor belonging to the Armed Detective Agency. 25 years old. She has a strong-willed and bold personality, and values her comrades. Her medical skills are extremely high, and she can treat severely injured people through her ability "Thou Shalt Not Die." However, the treatment requires first pushing the patient to a near-death state.