S P O T ／ SPOT-356

Sauna Hattatsu

サウナ発達さうなはったつ

In a quiet block of central Minamisoma — a city on Fukushima's Hamadori coast that the world came to know only through disaster — a former stand-up comedian has spent a decade building, by hand, one of the strangest bathhouses in Japan. Sauna Hattatsu is the work of Takehiro Kawaguchi, who took over his family's earthquake-shuttered rice shop in 2014 and, after his teenage son announced he wanted to build his own house, taught himself the earthbag construction method: stacking soil-filled sacks into walls. The result is a genuine cave sauna of packed earth and local driftwood — humid, radiant, storing heat like a kiln — that owes more to the steam baths of ancient cave-dwellers than to any Finnish blueprint. Step from the heat into the cold bath and you are watched: every wall is crammed with carved masks from around the world, a wooden congregation staring down at the 13°C groundwater. The whole compound is a single self-built organism — an eatery (Kawaguchi Shoten), a lodging wing (Suka), and a 'keep-adding museum' whose toilets are wallpapered with manga clippings that guests are invited to extend. It runs for exactly one group per day, by reservation only, so the entire bizarre world is yours alone. And from 2025, Kawaguchi intends to register the entire building as a Shinto shrine — 'Jinja Hattatsu' — turning a homemade sauna into a place of worship still very much under construction.