The 2011 Tōhoku earthquake and tsunami is both a personal catastrophe and a turning point in the novel’s investigative landscape. Remembered through Yasuyo’s losses and reflected in the weakened records and scattered companies surrounding nuclear-plant work, the disaster changes what can be rebuilt, what can be traced, and what remains beyond reach.

Destruction and Personal Aftermath

More than a decade after Kyoichiro Kaga’s visit, Yasuyo still shudders at the memory of the earthquake and the destruction in her neighborhood. She and her neighbors were among the fortunate, but many of her relatives lived on the coast and were killed in the tsunami. When she later went to lay commemorative wreaths, the scale of the devastation left her unable to take it in: the landscape had become ruins, with boats, cars, and houses jumbled together beneath mud. The disaster is thus recalled not as a distant national statistic but through the loss of relatives and the obliteration of familiar places.

The earthquake and the Fukushima Daiichi nuclear disaster also brought an immediate end to Yasuyo’s working life. With electricity, gas, and water cut off, she closed both of her establishments; reopening would have been difficult even if the utilities returned, since she expected customers to be slow to come back. Already over seventy, she treated the disaster as the point at which it was time to change course. Savings from the boom years and her state pension allowed her a modestly comfortable retirement, with occasional drinks with old friends and short trips.

Effects on the Investigation

The disaster’s consequences persist in the police inquiry into the identities and past employment of Shunichi Watabe and Mutsuo Koshikawa. The nuclear industry relied on long chains of contractors and subcontractors, making it hard to establish which small firms had employed particular workers. After the 2011 earthquake and tsunami, many of those smaller companies withdrew from the business altogether. Investigators consequently had to seek help from police stations around the country and gather recollections from former bosses, crew leaders, and workers.

The passage of time and the industry’s recordkeeping practices compounded that difficulty. Companies were required to retain employee documents for three years only for full-time workers; short-term contractors could leave little or no trace. Since workers were routinely hired through layers of intermediaries, sometimes under false names, the investigators could not assume that a missing record meant a person had never worked at a plant. The disaster therefore intersects with an older structural problem: an employment system in which responsibility and information were already dispersed, and in which the closure of smaller firms further narrowed the paths back to a worker’s identity.

Labor, Risk, and Displacement

The investigation’s account of nuclear-plant labor gives this background a human dimension. Workers could move from plant to plant through subcontractors, staying for a few months at a time in company dormitories before moving on. One worker described having no settled home and spending four years in this cycle. His description presents a workforce organized around temporary employment and precarious residence, a condition that helps explain why tracing past workers is so difficult.

The work itself could involve cleaning contaminated areas during inspections and maintenance. A worker described radiation control as an ongoing task, with cleaning done by scrubbing surfaces with cloths and brushes. These details make clear that the inquiry concerns not only names in company files but workers whose labor took place in hazardous environments and whose employment could be mediated through multiple subcontractors. The earthquake’s disruption of small firms compounds an existing fragility in how such workers were hired and documented.

Narrative Significance

The disaster operates on two connected scales. For Yasuyo, it is remembered through bereavement, the wrecking of the coastal landscape, and the practical impossibility of continuing her businesses. For the detectives, its aftermath is embedded in the conditions of the search: companies disappeared from the industry, and the old employment trail grew even harder to follow. The event is therefore not simply a backdrop to the murder investigation. It marks a break in local life while also deepening the uncertainty around a labor history already obscured by short-term contracts, subcontracting, and assumed identities.