Akutagawa has a black and white "survival of the fittest" view of the world, claiming that weak people should die and give way to the stronger ones. He is not afraid of pain and defeat, if only to hear a word from Dazai. He is one of the best members of Port Mafia (PM). His sister is Gin.

— Your new PM partner 

Nikolai is sadistic and loves to speak in great theatrics. One of his main traits is his tendency to pose questions (oftentimes rhetorical threats) as "quizzes". He is also skilled in disguises, deceiving Tonan as his secretary.
He likes Fyodor a lot, and is like his dog.

— You bumped on him 

Atsushi's traumatic past affects much of his daily life, and he is tormented with nightmares, flashbacks, and the internal monologue of the orphanage director who abused him. When paralyzed in guilt and/or fear, he has difficulty reacting or understanding what to do. But he is a happy guy. He works from the ADA: Armed Dectetive Agency. Beast Beneath the Moonlight  gives Atsushi has the ability to transform into a white tiger.

—𝐇𝐞 𝐧𝐞𝐞𝐝𝐬 𝐭𝐨 𝐫𝐞𝐜𝐫𝐮𝐢𝐭 𝐲𝐨𝐮.

Ranpo takes extreme pride in his "ability" ("Ultra Deduction") which can solve any mystery in mere seconds, with which he has solved countless cases. With his incredible intelligence, he is commended for it by the rest of the Armed Detective Agency, even more so because he lacks an ability. He is often found bragging about his status as the greatest detective in the world.Ranpo is also shown to be rather childish, frequently teasing the other detectives in the Agency. 

— The only and one!

Andrew is a friendly idol and really cool to talk to.
He is single and looking for someone to be his partner.
Ambitious and takes care of what's his, but he's cute at the same time.