Onagawa Nuclear Power Station becomes a crucial lead in the investigation into Shunichi Watabe: the last stop on the Ishinomaki Line points toward the station, while testimony links Watabe’s work to electricity and possibly nuclear power. Yet the trail leads into an industry where temporary labor, subcontracting, and incomplete records make a worker’s identity difficult to verify. The station thus matters not only as a possible destination, but as part of the system that could shelter a man living under another name.

Setting and Investigative Lead

Forensic testing of a photographed timetable found a particularly high concentration of fingerprints beside Ishinomaki Station. The page was from the timetable for the Sendai Line, which runs from Sendai to Ishinomaki. Investigators followed the route onward to Onagawa Station, the last stop on the Ishinomaki Line. With nowhere farther to travel on that line, they treated Onagawa as Watabe’s likely final destination.

The place name supplied a second clue: Onagawa meant the nuclear power plant. Kyoichiro Kaga connected the timetable to something he had heard from Yasuyo Miyamoto. Kaga’s mother, Yuriko Kaga, had told Miyamoto that Watabe’s job was related to electricity. Miyamoto could not confirm that it was nuclear work, but the route and the employment clue converged on the station.

From Hypothesis to Search

Kaga reasoned that, before the earthquake changed travel conditions, a worker based at Onagawa could travel to Sendai and back in about an hour and a half. He proposed that Watabe spent most of his time near the plant and went to Sendai on days off. Miyamoto’s account that Watabe had been away from Miyagi Prefecture for an extended period to work elsewhere also fitted the pattern of nuclear-plant maintenance workers moving between sites as jobs ended.

The task force consequently decided to examine people who had worked at Onagawa Nuclear Power Station. This was a working hypothesis, not proof that Watabe had been employed there. As the inquiry widened, investigators contacted smaller power companies and sought people who might recognize sketches of Watabe or Mutsuo Koshikawa. Police stations across Japan helped interview company owners, crew leaders, and former workers, while the task force pursued leads connected with other plants as well.

Records and Subcontracted Labor

The investigation encountered a basic obstacle: the events lay too far in the past for many employment records to survive. Companies were required to keep employee documents for three years, but that requirement applied to full-time workers, not short-term contractors. Nuclear work could pass through long chains of contractors and subcontractors, leaving responsibility for a worker’s employment difficult to trace. The account also notes that forged residence cards and work under false names were routine in this labor market. If Watabe was an assumed name, the absence of a clear record would not be surprising.

The scale of the subcontracting network compounded the problem. Many small firms had withdrawn from the industry after the 2011 Tōhoku earthquake and tsunami, further scattering the trail. Investigators confirmed that neither Watabe nor Koshikawa appeared in the radiation-work records they checked, but that did not rule out employment outside radiation-controlled areas or under other names. An industry expert considered work under those names in nuclear plants unlikely to have escaped such records if it involved radiation-controlled areas, while the broader search remained open.

Work, Identity, and Narrative Significance

A conversation with a nuclear-plant laborer supplied a concrete picture of the employment system the investigators were trying to navigate. Workers could be hired through very small subcontractors, housed in dormitories at each posting, and moved from plant to plant after a few months. One worker described having spent four years in this cycle. His account makes clear how a person with an unstable home and a difficult past could find work without a settled residence, while also showing how responsibility and information were dispersed among intermediaries.

The laborer described maintenance work as a sustained effort to clear radiation from contaminated areas, using cloths and brushes to clean surfaces. This detail places the suspected job in the physical work of plant maintenance rather than in an abstract employment category. It also clarifies why radiation-dose records mattered to the investigation: the work could entail exposure, while the subcontracting chain made it harder to identify the workers carrying it out.

Onagawa Nuclear Power Station therefore functions as both a geographic clue and an institutional setting. The timetable suggests where Watabe may have gone; testimony suggests why he might have gone there; and the structure of nuclear maintenance work helps explain why the name attached to him could fail to lead investigators to a person. Kaga ultimately used the accumulated connections between Watabe and Hiromi Asai to propose that Watabe was in fact her father, Tadao Asai, who had apparently faked his death. The station is not presented as proof of that identity, but the search around it helps expose the conditions under which an assumed identity could persist.