Sakurai, on Japan's Inland Sea: a bath in a cave, with a door one metre high. Inside, ferns burned until the stone was hot. Then the firing man put on a padded coat and a hood with a slit for the eyes, and soaked his straw sandals. His cuffs were burnt black. In he went: wet mats on the last flames, seawater by the bucket. Five minutes, and he stumbled out.

Who went in? Farmers, after the rice planting. They brought a sack of rice, stayed for days and called it resting the bones. Hooded like him, packed in the dark, no singing allowed. A dip in the sea, and back in. The children came too, against colds, their mothers said.

In the boom years most of the caves went cold. Not all: in Kagawa one stone bath is still fired, eight times a week. Its guest book for 2024 lists two visitors from Finland.

This is history, not a how-to: the old caves were very hot and short of fresh air.

Would you go in after the firing man?

Sources: Ehime Prefectural History (1984, 1986) and the Ehime oral history collection (1995) on the Sakurai stone bath; Maeda Katsuo, Ishiburo (1988), paraphrased; Kobayashi Hiroshi on the Tsukahara karafuro (2026).