Tradition: Japanese Mythology
Alternative Names: Okiku Bug; Okiku Mushi (於菊虫, おきくむし)
Category: Insect
The Myth
The Okiku mushi is a caterpillar-like yōkai with the torso of a human woman. It is associated with wells around Himeji Castle and is believed to have originated from the lingering vengeance of Okiku, the murdered servant girl whose ghost haunts the castle’s folklore. The creature is identified with the caterpillar of the Chinese windmill butterfly (Byasa alcinous), whose chrysalis was thought to resemble the body of a woman bound with ropes.
According to the tale of Banchō sarayashiki, Okiku was murdered by her lover. Her body was tied up and tortured before being thrown into a well at Himeji Castle. After her death, strange occurrences were attributed to her vengeful ghost. Among them was the sudden appearance of large numbers of unusual caterpillars. Because their chrysalises resembled a tied-up woman, people connected the insects with Okiku’s fate and believed they were manifestations of the resentment her spirit had left behind.
The butterfly is commonly known in Japan as the jakō ageha, but it also acquired the nickname Okiku mushi because of the popularity of the ghost story. During the Edo period, local shopkeepers near Himeji Castle reportedly sold the insects’ chrysalises as souvenirs to visitors at nearby shrines, further spreading the association between the caterpillars and Okiku’s tragic story.
Sources
“Okikumushi.” Yokai.com. https://yokai.com/okikumushi/