Mutsuo Koshikawa·Shunichi Watabe portrait

The Mutsuo Koshikawa/Shunichi Watabe portrait is an artist’s sketch used by investigators to identify a man whose names, history, and whereabouts do not align. Initially presented as a likeness of an unidentified person, it is shown to witnesses and people connected with Hiromi Asai. Its changing interpretation—from an uncertain clue to a likeness of a man already dead under another name—makes the portrait a focal point for the novel’s distinction between appearance and proof.

Identity and Investigation

The sketch enters the inquiry as an attempt to give a face to a man known through witnesses but not yet identified by name or photograph. Inspector Matsumiya shows it to Takeo Suwa, Hiromi’s former husband, asking whether it resembles anyone Suwa knows. Matsumiya explains that investigators have eyewitness accounts of the man but no established name or photograph; the drawing is a practical means of asking people to recognize him, not an identification in itself.

The broader investigation makes that uncertainty consequential. Mutsuo Koshikawa had rented his Tokyo apartment for nine years, yet had never updated his residence certificate. The previous address he supplied was in Maebashi, but investigators found nothing there to substantiate his account and suspected the address was false. When police searched his apartment, they found no phone, photographs, identity cards, credit cards, or letters that could establish who he was. The portrait therefore serves as a visual substitute for the ordinary records and personal traces that are missing.

The drawing’s evidentiary role is deliberately limited. When Kumi Hashimoto asks whether its subject is Michiko Oshitani’s killer, Matsumiya says the police do not know. Hashimoto worries that the figure resembles Seizo Naemura, illustrating how a sketch may prompt recognition while also directing suspicion toward the wrong person. Matsumiya withholds that the man depicted has himself been murdered. To the people being questioned, the drawing is an unexplained clue; to the investigators, it belongs to a case with facts they cannot yet disclose.

From Likeness to Identity

The portrait becomes more than a search aid when forensic work establishes a connection between Koshikawa and Shunichi Watabe, the name used by a man in Sendai. Fingerprints recovered from a timetable match those in Koshikawa’s apartment, objectively establishing that the two names belong to the same person. The number and placement of prints suggest that Watabe, rather than Kaga’s mother, had used the timetable most. That identification changes how the sketch is understood: it can now be associated with a man known by two identities, though the drawing itself did not prove the connection.

Kaga’s reasoning then reaches beyond the portrait. He argues that Hiromi Asai and Watabe had been connected for at least ten years, and that Watabe’s isolation, age, disappearance, and acquaintance with Michiko Oshitani make Hiromi’s financial support of him likely. Kaga proposes that Watabe was Hiromi’s father, Tadao Asai. The portrait participates in this reconstruction by giving investigators a likeness to show people who might recognize the missing link, but the proposed identity depends on relationships, records, and forensic evidence—not on resemblance alone.

The case’s history of false identity makes that caution essential. Tadao Asai was believed to have died by suicide, but the supposed death was not supported by official records beyond the files of Biwa Gakuen Orphanage. A newspaper account recorded that a body’s identity had been accepted after fingerprints on luggage were matched and Tadao’s daughter visually identified the body. Kaga suspects that another person died in Tadao’s place and that Tadao used the death to erase his own identity. The portrait’s subject, like the body in that older identification, cannot be securely named by appearance alone.

Recognition and Limits

Kaga’s effort to find Watabe through visual comparison is extensive but inconclusive. He gathers nearly five thousand photographs and recruits younger officers to search for someone resembling the sketch. He acknowledges that the task is difficult because different people see the man in the drawing differently. The scale of the search underscores the portrait’s double character: it is a concrete image that can be circulated, yet its likeness is unstable enough to resist reliable identification.

A separate photograph offers a revealing contrast. Kaga brings Kobayashi an image from the Nihonbashi bridge-washing ceremony, in which a woman in the foreground is clearly identifiable as Hiromi Asai. The bridge-scrubbing children and the adults taking pictures appear in the background, while the photographer’s chosen focus is Hiromi’s profile. The photograph supplies a recognizable image of a person whose connection to Watabe is under investigation; the sketch, by contrast, begins with a man whose identity is unknown. Both images invite investigators to read faces, but only the surrounding evidence can establish what those faces mean.

Narrative Significance

The portrait gathers several layers of uncertainty into one object: a witness-based likeness, a possible resemblance to Seizo Naemura, and, after forensic findings, a depiction associated with Mutsuo Koshikawa and Shunichi Watabe. Its meaning changes as the investigation changes, while the drawn face itself remains an imperfect guide. It can focus questioning and provoke recognition, but it cannot settle identity or guilt.

That distinction mirrors the case’s larger problem of separating names and appearances from verifiable identity. Koshikawa left almost no personal records in his apartment; Watabe’s connection to Hiromi is inferred from a long, private relationship; and the history of Tadao’s supposed death depends on a body identified through evidence that Kaga later questions. Against these gaps, the portrait is useful precisely as a question rather than an answer: it makes the unknown man available for comparison, while the investigation must test each comparison against records, fingerprints, testimony, and DNA.