Tucked between the hills of Yokosuka are the yato — residential alcoves that were, until recently, only reachable through a single entrance, their interiors hidden from the street. Built as the Naval Arsenal expanded through the Taishō and early Shōwa periods, these valleys are filled with the density of workers’ lives: houses pressed deep into the hillside, neighbourhoods that faced inward by necessity. Yato are frequently cited as a symptomatic landscape of Japan’s depopulation — places where decline has gone furthest and become most visible at once. In some areas, nearly 20% of houses stand empty: doors sealed, gardens returned to bush, houses stranded at the end of paths that no longer lead anywhere.
But this framing misses something structurally significant. The terrain of yato has a longer history, one that belonged to prehistoric communities of Jōmon and Yayoi periods, medieval-era clans that gave birth to the peninsula’s name Miura, followed by diplomats, merchants, and itinerant travelers who used yato’s trade and political routes connecting the coast to Edo. The modern yato communities took shape alongside the Naval Arsenal that drew workers, soldiers, and merchants from across the country. These histories did not arrive continuously, but they do not disappear either — their traces are inscribed onto the soil, the topography, and the landscape itself. Nor does the framing do justice to the yato’s rich ecology that gives this region a markedly higher satoyama index — a biodiversity indicator calculated based on habitat diversity — than the Tokyo metropolitan area or even many of its suburbs.
The collection of bamen departs from the premise that the yato areas are not a problem to be diagnosed, but a set of connections to be discovered, analyzed, narrativized, and shared to promote yato’s satoyama mosaic. It is an exercise in socio-ecological historiography that traces a richer past than the one condensed into naval ports, warships in the harbour, and commemorative sites — without dismissing what those sites hold. What it adds is a different frame: one in which human histories and ecological histories are not separate tracks but mutually shaping forces, each leaving its signature on the other. To do that, this project puts the theory of bamen (場面) into cartographic practice — connecting fragments of history, memory, and story recorded in books, memoirs, and local archives with physical locations in yato, while attending to the satoyama-satoumi mosaic that quietly sustains, while being sustained by, the lives lived and flourished on this land.
The labyrinthine valleys of yato, formed along the ridgelines of the Miura Peninsula’s hills and low mountains, were not always land. For most of its geological history, it lay under the sea — sediment settling for millions of years before the Philippine Sea Plate, subducting beneath the Sagami Trough, folded and thrust the seafloor upward into the hills that yato would later be built into. This particular fold of Japan’s Pacific coast, compressed and uplifted where three tectonic plates converge, preserves something unusual in its raised sediments: fossil chemosynthetic assemblages — the remains of communities that lived not on sunlight, but on chemical energy alone.
Chemosynthesis is the process by which bacteria and other organisms produce food from chemical energy rather than sunlight. It is the inverse of photosynthesis, in which plants, algae, and photosynthetic bacteria draw on sunlight to convert carbon dioxide and water into glucose and oxygen. Most chemosynthesis takes place in the deep sea, around hydrothermal vents and cold seeps, though related processes also occur along hydrological pathways within underground rock layers, and even in the anaerobic mud of flooded rice paddies at the surface. For example, just off the Miura Peninsula in Sagami Bay, a community of giant clams (Calyptogena) thrives around a cold seep, sustained by microbial communities that mediate the exchange of energy between chemically rich fluids and the surrounding seawater.
This form of metabolism — chemolithotrophy, which draws on the redox boundary between oxygen-rich and oxygen-poor zones — has drawn attention well beyond geology, geochemistry, and marine science. Astrobiologists see it as a working model for how life might survive the extreme conditions of other worlds, from Mars to Jupiter’s icy moon Europa.
For Metabolic Sociology, chemolithotrophy offers a more modest yet striking confirmation: that activity and metabolism are the origin of all life, from microbes to humans. It shows how shutai takes this same life-sustaining mechanism and extends it onto an ontological gradient rather than a redox one — evidence that life, at every scale, has evolved to generate energy and resources internally, alongside what it draws from outside itself, not only to survive but to produce the niches and ecosystems it comes to inhabit.
The bamen (場面) collected here sheds light to the socioecological significance of these geological and chemosynthetic landscapes. Geohydrological pathways — the underground routes along which groundwater, and the electron donors and acceptors it carries, connect land and sea — offer clues to what is happening beneath the surface, linking fossil seep, gas field, and living cold seep across scales of time we cannot otherwise perceive. Where the yato storymap weaves bamen from fragments of human memory and history, this storymap draws out bamen that trace a much older, deeper, and still-moving history underground.