Kunikida Doppo

As a member of the Armed Detective Agency, Kunikida was very professional and diligent when it came to his job, because to him, the reputation of the agency takes precedence over anything else. He constantly felt the need to organize, gather, and schedule everything, which is why he came off as somewhat strict and harsh during investigations.

He was also practical to a fault, as he almost considered abandoning a kidnapped Atsushi Nakajima, because the boy's presence might implicate the Agency.[11] He also once advised Atsushi to give up on the wanted Kyōka Izumi, lest his one-man boat might sink the both of them if he saves her,[12] though he soon encourages Atsushi later on when the latter shows resolve to rescue her.[13] Despite this, Kunikida was nonetheless a trustworthy and loyal detective upon whom many in the Agency relyed on because of his authoritative capability and responsible nature, which is why he was deemed as the Agency's next-in-line to becoming its President.

Kunikida trying to think of a plan Kunikida's reliance on his notebook.

He was almost never seen without his trademark notebook, which he believed to be an "ideal" and guide to life. He utilized it for several reasons, such as data-gathering, planning, making the world a better place, and most importantly, a medium for his ability, The Matchless Poet.

Dazai teases Kunikida Kunikida's typical annoyance towards Dazai.

Though he often appeared calm and careful, Kunikida was also known for his exasperated outbursts, which are primarily caused by his partner, Osamu Dazai, who constantly vexed him with his suicidal attempts. However, Kunikida never genuinely disliked Dazai. He acknowledged Dazai's skill and knowledge when first working with him, and he entrusted much of the Agency's strategies to Dazai. Kunikida extended similar faith to Ranpo Edogawa, as Kunikida actively participated in letting Ranpo believe Super Deduction is a real ability, since Kunikida, like the rest of his comrades, respected Ranpo's detective prowess and its value to the Agency.

Despite his well-rounded maturity level, Kunikida was also somewhat naïve and prone to easily believe Dazai's lies, including the "merit" of a noose when it comes to improving neck strength and that extreme shouting can cause hemorrhoids, which he later jots down in his notebook for future reference.

Kunikida becomes afraid Kunikida's breakdown seeing innocent people die in front of him.

Kunikida valued human life, as he strived to save all innocent people during dangerous events in Yokohama. He stuck to this belief after seeing young people injured or killed in front of him. As a result, Kunikida never thought killing his opponents is the only option, and constantly looked to solve problems without bloodshed. Due to Kunikida's passion to try to protect the city and its people, Ranpo believes he is the strongest and most virtuous person in the Agency. This calm front begins to crack when he was forced to "bend the rules", resulting in a mental breakdown.

Kunikida's mental state continued to deteriorate after the Cannibalism when being hunted by the Hunting Dogs, and he loses self-confidence and "the light he always sees on the other side of the mirror".[19] His ideals were challenged by Saigiku Jōno, who calls them "big and lofty as a hot air balloon". He believes that Kunikida's ideals will disappear if his comrades die, and that he will feel "relief".

Kunikida's sacrifice (manga) Kunikida sacrificing himself for his comrades.

Kunikida deeply thought about this statement, causing him to re-evaluate his ideals drastically, and he says that idealistic thought alone won't save lives and that they must choose to be more realistic. By the end, Kunikida made a self-sacrifice, sticking to his desire to keep his comrades alive and telling Tetchō Suehiro that he "won't let anyone ruin his plans" and that he shall let his ideals soar with his "life as fuel".[20]

From then on, Kunikida maintains his steadfast loyalty and faith in the Agency, more so when they reunited partially[21] and fully to take on their formidable adversary together.[22]