Hanzawa, whose full name is Makoto Hanzawa, is the main protagonist of the comedic spin-off series. He is visually represented as a classic black silhouette with featureless, glowing white eyes, a direct parody of the anonymous "culprit" character models used in the original Detective Conan series to hide a villain's identity until their reveal. He is originally from the countryside, specifically Izumo in Shimane Prefecture, and moves to the bustling, crime-ridden Beika City to pursue his single-minded goal: murdering the high school detective Shinichi Kudo. The exact nature of his grudge against Kudo is never fully specified, but it is implied that he holds the detective responsible for falsely accusing him of a crime in the past.

Despite his dark ambitions and a self-image as a natural-born criminal, Hanzawa is best described as an incompetent, ineffective, and cowardly individual. He frequently fantasizes about elaborate revenge schemes, such as using dynamite against a girl who laughed at him or strangling a landlord for imagined rudeness. However, he consistently lacks the courage to act on these impulses, often rationalizing his inaction by worrying that unnecessary murders would attract unwanted police attention and jeopardize his primary target. His life in Beika City, which he imagined as the perfect environment to hone his craft, instead sees him becoming a victim of the city’s absurdly high crime rate. He is horrified by actual violence, finding it frightening and disgusting, and he becomes easily spooked by living in apartments with a history of murder. He is deeply paranoid, perceiving the friendly residents, his landlord, and other familiar faces from the main series as intimidating, cold-hearted, and menacing. His social anxiety and insecurity about being a hick from the countryside frequently lead to awkward encounters, such as when he panics while trying to buy trendy clothes.

His role in the story is that of an ineffectual villain protagonist, and his narrative is driven more by the mundane struggles of daily life than by successful criminal enterprises. He lives in a shared housing complex, works a job at a video rental store, and owns a pet dog named Pometaro, whom he purchased with borrowed money. His key relationships are defined largely by his fear and misunderstanding of others. He is terrified of Ran Mouri, whom he privately nicknames the "crazy strong high-school unicorn girl" after witnessing her karate skills. He views Professor Agasa as a "mad scientist" due to the inventor's experiments with tranquilizers. Notably, he is completely unaware that Conan Edogawa and Heiji Hattori frequently follow him out of suspicion, as he is too lost in his own scheming to notice. His one short-lived partnership was with a fellow tenant named Hanbayashi, whom Hanzawa immediately recognized as having a "criminal aura," but the alliance ended when Hanbayashi attempted a murder without him. He also keeps in touch with his mother back in the countryside, who sends him supplies.

In terms of development, Hanzawa shows little to no progression toward achieving his goal of murder. He remains perpetually stuck in a loop of making plans, losing his nerve, and becoming distracted by the strange and dangerous world of Beika City. While he occasionally narrows down his target or devises a new approach, his efforts are always thwarted by his own ineptitude, bad luck, or the chaotic environment. Regarding his abilities, Hanzawa demonstrates a cautious and calculative mind, often weighing the risks and potential consequences of a crime before deciding against it. He also possesses a unique, unexplained ability to sense a "criminal aura" in others, which allows him to identify people with malicious intent. However, these minor skills are completely overshadowed by his overall incompetence as a villain.