Edo period

The Edo period is invoked as a time when the waterways of present-day Tokyo played a major role in both the economy and culture. That remembered importance contrasts with a modern city in which an expressway obscures the Nihonbashi River, making the river and the bridges above it easy to overlook. The reference also sits within a story where later disasters alter communities and where the loss of old records complicates the search for people’s histories.

Waterways and the Modern City

During a boat journey, Kaga points out that an expressway runs above the Nihonbashi River almost to the Sumida River. Built for the 1964 Tokyo Olympics when the necessary land could not be secured, the elevated route leaves the river nearly invisible on maps and makes crossing the bridges feel more like passing beneath a road than crossing a river. Against this altered urban landscape, Kaga remarks that the waterways must have played a major part in economic and cultural life during the Edo period. The observation gives historical depth to a river that modern infrastructure has pushed from view.

Memory, Disaster, and Historical Change

The novel places the Edo-period recollection alongside much later upheavals. More than a decade after Kaga’s visit to Sendai, the Great East Japan Earthquake and the Fukushima Daiichi nuclear disaster have profoundly changed Yasuyo’s circumstances. The earthquake and tsunami devastated coastal communities, killing many of her relatives; afterward, she went to lay commemorative wreaths among the ruins. With electricity, gas, and water cut off, she closed both of her establishments, and, now over seventy, treated the disruption as a point to change her life. These details do not describe the Edo period itself, but frame historical time as something registered through altered landscapes, livelihoods, and memory.

The Limits of Recovering the Past

The same concern with what time leaves behind appears in the investigation into Shunichi Watabe’s identity. Sakagami explains that the work at the Onagawa nuclear power plant happened long ago and that records may no longer exist: employers’ retention duties cover only three years and do not apply in the same way to short-term workers. Because the industry relies on layers of contractors and subcontractors, workers may be hired under false names, making a trace difficult to find. Set beside Kaga’s reflection on waterways whose former importance has faded from everyday awareness, this obstacle underscores the novel’s broader contrast between a past that shaped the present and the fragmentary evidence through which that past can be known.

Narrative Significance

The Edo period is a brief historical reference rather than a developed setting. Its importance lies in the contrast it supplies: waterways once central to urban life are now obscured by infrastructure, while modern disaster and vanishing records make other histories difficult to recover. The novel uses that contrast to connect visible changes in place with less visible losses of memory and evidence.