Yukito Ayatsuji

Ayatsuji is a man of average height and build. He has short, wavy blonde hair and sharp, gold eyes. He wears a pair of half-rimmed, light-colored sunglasses, and a black hat. He also wears a jacket with a yellow ochre base with a red collar, a white shirt with a vermillion-based checkered border and a gray knit vest, dull orange checkered knickerbocker pants, and beige boots.

Ayatsuji often presents himself as a cold and emotionless man. He is considered to be fairly odd and detached from others, preferring to spend his spare time in his basement full of dolls. Beneath his calculating and snide exterior, he appears to have a kind side to those he forgives, such as keeping a cat and loving it. He is not talkative unless in regard of insulting someone, and tends to make snide remarks and chide others for their lack of understanding. Ayatsuji can be rather expressive and playful, doing silly gestures such as imitating a dog to respond to Tsujimura's statement of reporting him to her higher-ups. Ayatsuji also thrives off others' reactions, claiming he wants to preserve their bitter expressions via a doll. He frequently teases others, an example being with Tsujimura about changing her into a maid uniform and being his servant, and for fun, ordering her to lick some leaves and showing disappointment when she refuses.

Ayatsuji is highly intelligent and observant. He has solved 50,000 cases, and when deducing, he remains blank-faced and unexpressive, using his wit and logic to outsmart his opponents, and he easily succeeds in finding the truth. He is dubbed the “Homicide Detective” and carries a deathly and imperturbable air, and his ability is dangerous enough to be seen as a threat by the government and to be put on the list of Extremely Dangerous Ability Users, constantly being monitored by snipers and agents. Due to his rather cocky air, he calls people simple-minded and doesn't hesitate to let people know of their "lack of intelligence" when he explains a case. Additionally, he does not take higher-ups seriously and flaunts his more rebellious streak, ignoring orders from the Special Division of Unusual Powers. When confronted with his defiance by Tsujimura, Ayatsuji tends to delay the topic and distract her.

Despite his aloof persona, Ayatsuji occasionally breaks his poker face. He show fragments of emotion and his harshness tends to alleviate slightly. Ayatsuji displays anger and fury when seeing a couple commit a double suicide in front of him, and will sometimes express his shock or hesitance. He also appears to harbor grievances towards his ability to a certain degree. Despite his coldness and teasing remarks, he deeply cares for those he is close to and occasionally shows a rare side of himself towards them, such as when he plans to give his life to ensure their safety.

He appears to have a smoking habit, almost always seen holding a kiseru smoking pipe.