Tradition: Japanese Mythology
Alternative Names: Bikki no Yomekko, Frog Wife, Kaeru Nyobo
Category: Frog
The Myth
Kaeru Nyōbō, meaning “frog wife,” is a magical frog that transforms into a human woman to marry a human man. In her human form, she behaves like an ordinary wife, but she is usually extremely small and fragile, sometimes no taller than a child of three or four years. Although willing to help with household chores, she lacks the strength to perform heavy work. As long as her true identity remains hidden, she can live happily with her human husband for many years. However, if he discovers her secret and sees her transform back into a frog, the marriage ends in tragedy.
One legend tells of an impoverished old man and his son who desperately wished for a wife for the young man. One day, a tiny woman arrived at their door and asked whether they would accept her as a bride. The delighted father welcomed her, and she married his son. The woman was soaking wet despite the absence of rain, but the family warmed her by the fire and accepted her despite her unusual size. She could not perform heavy household work, yet the men were satisfied with their new family member.
Some time later, the woman needed to attend a memorial service for her father. Although they were poor, her husband and father-in-law gave her a sack of rice to bring as a gift. The load was so heavy that she was crushed flat beneath it. The men removed rice until only five cups remained, allowing her to regain her normal shape and carry the smaller load. Suspicious of her strange weakness, the old man told his son to follow her. The young husband watched her travel deep into the mountains until she reached a marsh, looked around, and leapt into the water. Unable to see her beneath the surface, he listened to the croaking of frogs and realized that they were speaking. His wife explained that the sack of rice had delayed her, and the frogs began chanting Buddhist prayers for the memorial service.
Horrified to discover that he had married a frog, the young man threw a rock into the water, striking the frog priest and abruptly silencing the prayers. He returned home and told his father what had happened. When his wife arrived later that night, she explained that a huge rock had fallen from the sky and struck the priest during the ceremony. Her husband confronted her, revealing that he had witnessed everything and had thrown the stone himself. The woman was devastated that her secret had been exposed. She covered her face in embarrassment, transformed back into a frog, and hopped out of the house. She was never seen again. The tale ends with a warning that one should not accept just anyone as a marriage partner simply because one is desperate to find a spouse.
Sources
“Kaeru Nyōbō (蛙女房).” Yokai.com: The Database of Japanese Folklore. https://yokai.com/kaerunyoubou/