According to the japanese folklore, geya nyūdō are small, subterranean people who make their homes beneath human settlements. They are as small or smaller than human children, and almost always have a smile. Geya nyūdō live in old wells or in holes beneath peoples’ houses. When the home’s owners are away, they sneak into the house through the floorboards and eat the owner’s food, then sneak away before the owner returns.

Geya nyūdō are not hostile, nor do they bring bad luck to a house like some yōkai. They try to remain hidden and rarely interact with humans, although signs of their trespassing can be obvious; they often leave unwashed cooking utensils, dishes, and scraps of food behind when they leave. Homeowners usually suspect that neighbors or other humans have broken in to steal their food. But if they check under the floorboards and discover a hole in the ground, it is possible to capture the geya nyūdō with traps, or simply by reaching into the hole and grabbing them. If captured, they do not put up a fight. Instead, they just smile at their captors.

Geya nyūdō are well known yōkai in Kuwana, Mie Prefecture, and are also said to be found in Fukui Prefecture. A geya nyūdō account is found in Shin kaidan sanbon fude, an Edo period collection of tales.

Long ago there was a hermit monk named Ryōden. One day he had to travel far away, so he closed up his house tight and locked the door. He returned home after dark to discover a fire burning under his cooking pot. He looked under the lid of the pot and was surprised to find rice cooking in it. Ryōden thought that the local kids must have played a prank on him.

Thereafter, every time he left the house, Ryōden returned to find leftover cooked rice. Sometimes there were dishes scattered too. When Ryōden told his landlord about this, the landlord was sure it was the work of a kitsune. They gathered some men and searched for a fox hole. Lifting up the tatami mats and prying up the floorboards, they discovered a deep hole. Inside was a little monk, who looked about 80 years old, and was barely 90 centimeters tall.

The landlord dragged the priest out of the hole. It looked at everyone and grinned at them. They questioned the monk, but it just smiled back at them and didn’t seem at all uncomfortable. Several young people gathered, and they decided to kill the strange creature. But then an old man recognized it as a geya nyūdō and remembered a tale from his youth. A creature like this appeared at the house of the lord of Echizen Province. While it was playing in the garden, a samurai shot and killed it. He explained that it was harmless, and there was no reason to kill it. He convinced them to just take it somewhere far away. The townspeople chased it 8 kilometers away from the village and left it.

Six years later, the creature was seen again in an old well at a temple. The well had dried up, and when the went to fill it in, they discovered a tiny person living inside. It was the same geya nyūdō from before. Its appearance had not changed one bit.

Geya nyūdō are also called mushō, which means “without flaw”. This is due to the fact that they can live for a very long time without showing any signs of aging.