Nemuro Haru, the wife of the missing man. Short, slender, and with a husky voice and a freckled face, she drinks beer often and seems to live in an alcoholic daze, often talking to herself. She initiates the search for her husband.
Nemuro Hiroshi’s brother, also nameless. He is a mysterious character who appears to be involved in homosexual prostitution, blackmail, protection rackets, and other shady projects. He carries a blue and silver badge, apparently a gang insignia. He is insistent about the search for his brother and trails the private detective around until he himself is killed. The detective questions the true relationship of this character to the wife throughout the novel.
Tashiro, a young clerk in Nemuro Hiroshi’s company. He is an unattractive man with a bad complexion, shifty eyes, and thick glasses that he is constantly pushing up. A man who feels inferior and ignored, he confuses the investigation by suggesting that the missing man photographed nude models, then confesses that he himself is a compulsive liar. His suicide forces the narrator to resign as a detective.
Nemuro Hiroshi, a fuel dealer who has been missing for six months. A photograph of him shows a long, asymmetrical face with a sad expression. His employer describes him as a serious, steady, and honest worker. He has a sideline as a car mechanic and a mania for collecting professional licenses–for example, as a film projectionist, a secondary school teacher, and a radio operator. He is never found, but the search for his whereabouts drastically changes the lives of the other characters.
The chief, the narrator’s boss. As head of a private investigation agency, he is extremely careful not to let his agency get entangled with the police and warns his operatives to give their clients only what they want and not to invade their privacy. The narrator eventually gives up his job and loses his purpose in life because he realizes that his chief’s priority is to stay detached from cases and make money.
Toyama, a taxi driver. He bought a car from Nemuro Hiroshi, and he enters the investigation because he returns a raincoat that he found in the trunk of the car. His answers in the interrogation by the narrator provide important narrative and thematic information.