Translation: blood clot
Alternate names: kekke
Habitat: under the floorboards of its birth house
Diet: its own mother
Appearance: Kekkai are a kind of sankai—childbirth monster—from Saitama, Kanagawa, and Nagano prefectures. They are small and ugly, resembling a monkey. Their hair is said to grow in backwards, and they have two tongues: one red and one white. They are sometimes born from pregnant mothers instead of human babies.
Behavior: When a kekkai emerges, covered in blood and amniotic fluid, it quickly scampers away from its mother and tries to escape. This is most often accomplished through the irori, or earthen hearth, a common feature in old country houses. It either burrows down beneath the floorboards, or climbs up the long pothook which hangs above the irori and flees. If the kekkai is able to escape, it will return later to kill its mother while. It does this by burrowing up through the floorboards and into its sleeping mother, tearing her apart.
Interactions: A few traditional precautions exist to protect against kekkai. The most important is preparation. A large shamoji—a spatula—is placed by the irori. When the kekkai tries to climb up the pothook, it must be swatted down and caught before it has a chance to escape.
Another common precaution is to surround the floor around the mother with byōbu—folding screens—to prevent a kekkai from escaping. This practice is the source of a play on words surrounding this yōkai’s name: the byōbu creates a spiritual barrier, or kekkai (結界), which prevents the kekkai from escaping.
Origin: Kekkai are almost certainly a way to explain the dangers surrounding childbirth and the existence of birth defects. Before modern medicine was invented, death from complications relating to childbirth was not uncommon. A grieving family might be easily convinced that a mother’s death was caused by some evil spirit—some kind of spiritual punishment for the family’s sins. Similarly, it is not hard to imagine how earlier cultures might have seen premature, stillborn, or deformed babies as monsters. Referring to them as yōkai may have been an attempt to understand the unknown and unexplainable.